General engine questions/issues that aren't specific to the other categories
By kingkong559
#325165 Put a walker cat converter on and smogged it this morning. Passed just fine at 25 mph but barely passed at 15 mph. Why is that?

Here's a link to my test results:

http://i1219.photobucket.com/albums/dd4 ... 1213-1.jpg


Since I had no choice but to pick up a universal cat, I had the muffler shop weld the cat. After that it went straight to the smog shop cause they're both right next to each other. I did have a chance to let the car idle for 10 mins before the test.
By jpnzbtl
#332006 Very long story, but the results are below. I have a free retest within 30 days. I don't have a cat yet, but used to pass with my stock and built GSR without one. I have to make a cat to fit my exhaust since I have a JDM Ex Manifold with the 2.5 in outlet, currently using a spoon cat jack which is 12in. USDM Type R cat is longer. Any help is appreciated.

My intake had a broken PCV pipe, and I had to add a nipple for the purge solenoid valve to the canister.

Limits
CO HC NO

1.10 275 3600
----------------------------------------
Test 1(Baseline) 6/4/12

CO HC NO

1.42 537 6124
-------------------------------------------
Test 2 (Oil Change, New plugs) 1/9/13

CO HC NO

1.28 436 4854
----------------------------------------------
Test 3 (Fixed Intake PCV and Purge ports , new O2 sensor) 5/13/13

CO HC NO

1.24 448 1403
-----------------------------------------------
Test 4 (Seafoam intake, Set timing to 18btdc, Set TPS .5v)

Waiting to test.
By Axix23
#337615 I just failed my emissions on high nox readings. What I did to pass was:

1. I filled up on 93 octane gas(I normally run 87)(drive it for around 20 miles)

2. Retarded ignition all the way on the distributor

3. Fixed my broken vaccum line to my purge shut off solenoid(behind the throttle body area)

My Nox readings dropped from 1900ppm down to 823ppms.
Passing is : 1235 ppms.


Make sure you advance timing back to stock when your done.

Another trick is put 99.9% alcohol into your gas tank with 93 Octane and run it for 10-12 miles. It will read a super low Nox value...
User avatar
By suspendedHatch
#337643 Why not getting it running properly instead of cheating the system?

You're not concerned about mileage, power, and longevity? Seems like these forums would be an unlikely place to find someone like that.
By mars
#346463 Hi SuspendedHatch,
My 92 Civic VX D15Z1 49 state(with EGR) failed smog @ 25 due to high HC. Can u help, plz. Here are the results:
15mph RPM 2474 CO2 14.3, O2 0.1, HC max 96 meas 28, CO max 0.59 meas 0.03, NO max 859 meas 689 Pass

25mph RPM 2319 CO2 8.7, O2 7.7, HC max 79 meas 146, CO max 0.51 meas 0.02, NO max 798 meas 382 FAIL

Replaced sparkplugs, O2 sensor with new OEM Dealer, ECU P07(eBay- used) Retested

15mph RPM 2452 CO2 14.4 O2 0.0, HC max 96 meas 37, CO max 0.59 meas 0.04, NO max 859 meas 434 PASS

25mph RPM 2209 CO2 9.0, O2 7.3, HC max 79 meas 123, CO max 0.51 meas 0.02, NO max 798 meas 516 FAIL

For both above tests, Timing is 14 BTDC according to smog Tech

I removed the brand new spark plugs after about 200 miles and #4 (close to the distributor) looks white and nice, #3 & 2 partially black, and #4 completely black.
Any help is appreciated.
User avatar
By suspendedHatch
#346711 So for background info I posted this thread in 2008 and haven't worked in safety/emissions in over 4 years. Honestly, when I have an emissions problem I'll often reference this thread, as I often reference some of my other threads on other sites for other info and of course my own damn website :lol: I never imagined I would still be messing with Hondas and answering questions on forums 6 years later (got into the game in 2002 actually) but I just bought another VX winter 2013 and this is a great little community so here goes:

EVERYONE IN THIS THREAD SHOULD READ THIS

These cars are all over 20 years old and in the hundreds of thousands of miles. A simple tune up (oil, spark plugs, rotor, cap, PCV, check wires, ignition timing, fuel filter, check O2 sensor, check idle speed) just doesn't cut it anymore. If you haven't even gotten this far, put away your smart phone and come back when you have.

(On your VX make sure you have the right spark plugs in there and only use NGK or dealer plugs. Most VXs have the wrong ones since the application is often incorrect and most parts stores stopped carrying the correct plugs (try amazon).)

After the basics, you still need to do some reconditioning before you can even get a baseline for diagnosis.

All VX's and most other models need the intake manifold removed and thoroughly cleaned, especially around the EGR ports. Remove the MAP sensor as it is sensitive to cleaners and solvents. You'll need a new throttle body gasket and intake manifold gasket and you can't count on the bigger auto parts chain stores having them anymore. Oven cleaner works reasonably well for cleaning baked on gunk, but it will still require a lot of soaking and brushing. Aircraft remover helps get the old gasket off along with a razorblade scraper and a fine grit sand paper on a die grinder. Also clean the head ports and injector holes a bit but don't get a bunch of gunk into the cylinders and don't spray too much throttle body cleaner in there or you'll have a fun time drying it out so it can start again. While you have the manifold off, pull the breather box off, clean it out and replace the O ring to the block. You'll need the exact right size O ring.

All EGs need fuel injector service. I like Injector Rehab. VXs and CXs have smaller injectors than all other D and B series (which are all 240CC) so keep this in mind if you plan to send junkyard injectors in to minimize downtime.

All EGs need valve adjustments (see my other thread). You will find that each valve is inconsistent with the next and that the intake side is often too tight and the exhaust side too loose. This is wasted power potential, wasted gas, preventable emissions, premature death for your O2 sensor and cat converter, and it's hard on your engine because some cylinders are running rich and others lean.

Put 1/3rd can of Seafoam in the fuel tank, oil, and suck the other 1/3rd in the brake hose. Before you do the latter, remove your O2 sensor and put a spark plug in it's place to plug the hole. PS, have fun getting that O2 sensor out w/out stripping it. Get yourself an O2 sensor wrench (not socket) and a thread chaser.


Now get your car tested, note which gas failed and refer to page one. Honestly I would be VERY surprised if you failed after this and if you did, there's not a whole lot else you can do. All you're left with is an intermittent fault ie coil, ignitor or the piston rings are shot and you need an engine swap :?
User avatar
By suspendedHatch
#346712
mars wrote:Hi SuspendedHatch,
My 92 Civic VX D15Z1 49 state(with EGR) failed smog @ 25 due to high HC. Can u help, plz. Here are the results:
15mph RPM 2474 CO2 14.3, O2 0.1, HC max 96 meas 28, CO max 0.59 meas 0.03, NO max 859 meas 689 Pass

25mph RPM 2319 CO2 8.7, O2 7.7, HC max 79 meas 146, CO max 0.51 meas 0.02, NO max 798 meas 382 FAIL

Replaced sparkplugs, O2 sensor with new OEM Dealer, ECU P07(eBay- used) Retested

15mph RPM 2452 CO2 14.4 O2 0.0, HC max 96 meas 37, CO max 0.59 meas 0.04, NO max 859 meas 434 PASS

25mph RPM 2209 CO2 9.0, O2 7.3, HC max 79 meas 123, CO max 0.51 meas 0.02, NO max 798 meas 516 FAIL

For both above tests, Timing is 14 BTDC according to smog Tech

I removed the brand new spark plugs after about 200 miles and #4 (close to the distributor) looks white and nice, #3 & 2 partially black, and #4 completely black.
Any help is appreciated.


My best guesses are wrong plugs, incorrect ignition timing (14 may be within spec but get it right on the red line), too high of octane, or you need a valve adjustment. You almost certainly need your injectors serviced. These last two suggestions could account for the difference in spark plug deposits between cylinders.
By MG6
#346722
suspendedHatch wrote:So for background info I posted this thread in 2008 and haven't worked in safety/emissions in over 4 years. Honestly, when I have an emissions problem I'll often reference this thread, as I often reference some of my other threads on other sites for other info and of course my own damn website :lol: I never imagined I would still be messing with Hondas and answering questions on forums 6 years later (got into the game in 2002 actually) but I just bought another VX winter 2013 and this is a great little community so here goes:

EVERYONE IN THIS THREAD SHOULD READ THIS

These cars are all over 20 years old and in the hundreds of thousands of miles. A simple tune up (oil, spark plugs, rotor, cap, PCV, check wires, ignition timing, fuel filter, check O2 sensor, check idle speed) just doesn't cut it anymore. If you haven't even gotten this far, put away your smart phone and come back when you have.

(On your VX make sure you have the right spark plugs in there and only use NGK or dealer plugs. Most VXs have the wrong ones since the application is often incorrect and most parts stores stopped carrying the correct plugs (try amazon).)

After the basics, you still need to do some reconditioning before you can even get a baseline for diagnosis.

All VX's and most other models need the intake manifold removed and thoroughly cleaned, especially around the EGR ports. Remove the MAP sensor as it is sensitive to cleaners and solvents. You'll need a new throttle body gasket and intake manifold gasket and you can't count on the bigger auto parts chain stores having them anymore. Oven cleaner works reasonably well for cleaning baked on gunk, but it will still require a lot of soaking and brushing. Aircraft remover helps get the old gasket off along with a razorblade scraper and a fine grit sand paper on a die grinder. Also clean the head ports and injector holes a bit but don't get a bunch of gunk into the cylinders and don't spray too much throttle body cleaner in there or you'll have a fun time drying it out so it can start again. While you have the manifold off, pull the breather box off, clean it out and replace the O ring to the block. You'll need the exact right size O ring.

All EGs need fuel injector service. I like Injector Rehab. VXs and CXs have smaller injectors than all other D and B series (which are all 240CC) so keep this in mind if you plan to send junkyard injectors in to minimize downtime.

All EGs need valve adjustments (see my other thread). You will find that each valve is inconsistent with the next and that the intake side is often too tight and the exhaust side too loose. This is wasted power potential, wasted gas, preventable emissions, premature death for your O2 sensor and cat converter, and it's hard on your engine because some cylinders are running rich and others lean.

Put 1/3rd can of Seafoam in the fuel tank, oil, and suck the other 1/3rd in the brake hose. Before you do the latter, remove your O2 sensor and put a spark plug in it's place to plug the hole. PS, have fun getting that O2 sensor out w/out stripping it. Get yourself an O2 sensor wrench (not socket) and a thread chaser.


Now get your car tested, note which gas failed and refer to page one. Honestly I would be VERY surprised if you failed after this and if you did, there's not a whole lot else you can do. All you're left with is an intermittent fault ie coil, ignitor or the piston rings are shot and you need an engine swap :?


sweet info! I had my Uncle VX after he passed away and it was a pretty sweet ride for commute.

it had emission failure issue and it came down to O2 sensor after perform all above without a code being thrown out. Get quality o2 sensor as this is one of the leading issue that is different from model (dx, ex, or so as you know).

also, with smog becoming stricter, find a smog place that you trust because I wasted a good amount of money for a stupid tech trying to fail my testing because he doesn't know about the vx model beside it emits lower emission or gas saving with cause emission to report differently.

lesson learn.
By Earlybird
#348404 suspendedHatch, first off GREAT write up.

I have a 95 Ex Coupe over here in Texas that has failed twice on the HC & CO

1st attempt numbers
******** 25MPH ****************************15MPH*************
***standard********actual************standard********actual******
(HC) 167 ***** 228 Fail **** 173 ******* 234 Fail
(CO) 0.94 ***** 1.76 Fail **** 0.97 ***** 1.41 Fail

2nd attempt
167 ***** 173 Fail ****** 173 ******* 196 Fail
0.94 ***** 0.91 Pass ******* 0.97 ******* 1.82 Fail

Prior to first test 02 Sensor replaced (check engine light was on) Thermostat replaced, Harmonic Balancer replaced. In between the first and second test I did new plugs, wires, cap and rotor. running Super Unleaded. Just replaced radiator. Is it time for a new Cat?
User avatar
By suspendedHatch
#348433 States like Texas (that only half-ass it to get federal money but don't give a rats ass about air quality) make it difficult to diagnose because they don't measure the O2 content. For the most part I can only give you suggestions to try.

If you put a new cat on it, you might pass but you'll ruin the cat and need a new one for the next test. Your HC are ridiculously high. You're not burning the fuel. Are you running 87 octane? You didn't put any of that crap guaranteed-to-pass stuff into your tank, did you?

Set your base ignition timing to spec (red line in between white lines on crank pulley). If it wont adjust to the red line, verify that you have the correct distributor.

You didn't put any gimmicky wires on I hope. Magnecor, NGK or OEM are the only ones I'd recommend (in that order). Cheaper wires will work but need to be replaced every other year. Nology-like wires, Bosch-four-prong-like "performance" plugs will often cause super high HCs because you wont be burning all the fuel.
By jehprofessional01
#348481 Failed smog twice

Initially failed and needed to adjust timing, repair PCV hose, gas cap and high NO.
Here are those readings:
HC: 49/42
CO: .19/.22
NO: 912/782


Had all of the repairs done and still failed :(
HC: 52/45
CO: .22/.17
NO: 1212/961

Had the fuel filter replace a few months ago, but may be time for a tune up :/



Help please.
User avatar
By egsedanguy
#348487 what year is your car? Have you replaced the o2 sensor? Possible leak near the o2? Also If you have not done a tune up prior to smog then that would be a good idea. New plug, cap n rotor and new wires. Fresh oil and a fresh tank of good gas. I have always ran premium befor smog and I also do a fuel cleaner prior to going to get the injectors clean. Also make sure tires are at the correct pressure. Low psi can cause issues cause they wont roll as freely. 1 trick I use and has worked multiple times( may not every time) is run 5 gal of 91 with 1 gal of e85. I got my last prelude to pass even tho the cat was done. not by mutch but it passed. Just some ideas for ya. Just trying to save ya from a cat.
By jehprofessional01
#348488
egsedanguy wrote:what year is your car? Have you replaced the o2 sensor? Possible leak near the o2? Also If you have not done a tune up prior to smog then that would be a good idea. New plug, cap n rotor and new wires. Fresh oil and a fresh tank of good gas. I have always ran premium befor smog and I also do a fuel cleaner prior to going to get the injectors clean. Also make sure tires are at the correct pressure. Low psi can cause issues cause they wont roll as freely. 1 trick I use and has worked multiple times( may not every time) is run 5 gal of 91 with 1 gal of e85. I got my last prelude to pass even tho the cat was done. not by mutch but it passed. Just some ideas for ya. Just trying to save ya from a cat.


My car is a 1993. I've not replaced the sensor yet as it could be a number of things. Don't want to waste money and time. I think the best idea is to get the tune up and work from there.

Thanks for the info.
User avatar
By egsedanguy
#348489
jehprofessional01 wrote:
egsedanguy wrote:what year is your car? Have you replaced the o2 sensor? Possible leak near the o2? Also If you have not done a tune up prior to smog then that would be a good idea. New plug, cap n rotor and new wires. Fresh oil and a fresh tank of good gas. I have always ran premium befor smog and I also do a fuel cleaner prior to going to get the injectors clean. Also make sure tires are at the correct pressure. Low psi can cause issues cause they wont roll as freely. 1 trick I use and has worked multiple times( may not every time) is run 5 gal of 91 with 1 gal of e85. I got my last prelude to pass even tho the cat was done. not by mutch but it passed. Just some ideas for ya. Just trying to save ya from a cat.


My car is a 1993. I've not replaced the sensor yet as it could be a number of things. Don't want to waste money and time. I think the best idea is to get the tune up and work from there.

Thanks for the info.



Ya start with a tune-up thats the best thing. 1) Its good to do 2) It eliminates the easy stuff. An o2 should be about 70-80$ or get one from a friend that you know works and swap it for the test. :thumb: even if you have a friend with a good cat and swap that on also :thumb:
User avatar
By suspendedHatch
#348509 "Premium" gas is not any better than any other grade of gas. By law it has all the same additives as the other grades. It's a higher octane, which is only a good thing if you have a high compression or turbo engine. The higher the octane, the harder it is to burn. If your engine was designed for 87 octane, and you haven't changed the pistons or added forced induction, use 87 octane.

All the D series and the B18b use 87 octane. The B16 and B18C variants use 91 and sometimes benefit from 93.

Running a higher octane than necessary will sometimes help with NOx but will also raise your HC.

In high elevations, 85 is available but I still use 87 as per the owners manual.

This thread is focused on getting your car running well and legitimately passing smog. There are ways to trick the smog machine, but in the end you still have an engine that isn't getting the most power and fuel economy it should be getting.