He is the quick version: 1995 Max 5-spd. Completely stock. First time I had a check engine light for the EGRC solenoid valve but the car ran fine and I went to get it tested. The car failed HC and CO %. Thinking the problem was related to the EGRC solenoid valve, I replaced it. The check engine light is now off and I went back to have it retested and it failed HC and CO% again and the HC and CO% numbers were actually a bit worse. Car has had recently spark plugs and air filter. Any ideas?

Here are the numbers:
25/25 Test
HC ppm reading: 195 allowed: 120 FAIL
CO % reading: 5.27 allowed: 0.67 FAIL
NO ppm reading: 135 allowed: 848 PASS
CO+CO2 % reading: 16.8 allowed: 6.0 min PASS

50/15 Test
HC ppm reading: 177 allowed: 124 FAIL
CO % reading: 5.06 allowed: 0.69 FAIL
NO ppm reading: 143 allowed: 937 PASS
CO+CO2 % reading: 16.8 allowed: 6.0 min PASS

*UPDATE* 12/11/09: I replaced the front left oxygen sensor since I was getting the 0806 fuel injection malfunction (left bank) code along with a 0303 oxygen sensor code but no check engine light. I just got back from retesting the car. The numbers are a whole lot better but the car still failed

Here are the numbers from retesting it:
25/25 Test
HC ppm reading: 140 allowed: 120 FAIL
CO % reading: 1.40 allowed: 0.67 FAIL
NO ppm reading: 240 allowed: 848 PASS
CO+CO2 % reading: 15.5 allowed: 6.0 min PASS

50/15 Test
HC ppm reading: 56 allowed: 124 PASS
CO % reading: 0.01 allowed: 0.69 PASS
NO ppm reading: 107 allowed: 937 PASS
CO+CO2 % reading: 14.9 allowed: 6.0 min PASS

Any ideas? Look like I'm still getting the 0806 code with I check but no check engine light on. The car passed on the 50/15 test but failed on the 25/25 test? How does that work?

 

wish I could help you shamus but I've never lived in a state that had any sort of emissions so I've never bothered to really learn about emissions systems. I just remove them because they are an annoyance lol. good luck man

 

If you haven't changed your oil lately change it and retest, sometimes that can cause those high readings.

 

hmmmm.......I've never heard that one before. I do need to change my oil. Its been 3500-4000 miles, but I seriously doubt the oil has anything to do with the readings being that far off.

 

I hear ya Neal. Thanks

 

wait...a 95 doesnt have to go through emissions iirc its from 96 on up. unless it varries from state to state in NC they ask u what year the car is if they hear 95 they dont plug up the machine. its also kinda strange, since i have come to find out my car is technically a 95 i have a test pipe on it without a spacer and it breezed through emissions.

 

Here in Ga, 95 and older have to be tested on rollers with the reader up the tail pipe. 96 and newer get plugged into the computer and they just scan the car for codes.

 

oh damn that sucks better go register those cars in SC

 

I did have an injector die on me about a month ago, but I replaced it with a used one. Any ideas whats causing the HC and CO% to so off? The car seems to drive fine. The emissions place will let me come back one more time before this weekend and test for free.

 

O2 sensors might be getting lazy in their old age.

 

I agree with this. My 95 is now exempt from the sniff test here in MA (a recent change in our annual inspections). But from 94 to the last couple of years (when the law was changed) I never had trouble passing the mandatory, every other year emissions test. Maybe it had nothing to do with passing the test, but I ALWAYS made sure that I changed my oil just before getting an inspection done. Also make sure the car is well warmed up when you get it done.

 

same here I live in MA and thank God 95 and below don't need to pass emmisions !!! but yea try changing the oil and use NGK spark plugs and make sure the car is warm up to normal temp that helps allot too ! also try to go when the tank is very low and use the highes octane like 94 and it should pass if it doesn't move to MA ha ha no is freaking cold here !!

 

I changed the plugs with OEM ones maybe 15,000 miles ago and the car was indeed warmed up with I tested. I seriously don't think the oil has anything to do with the car not passing. The car has maybe 3500 miles since my last oil change. Possibly if the car had like 10,000 miles since the last oil change, but not 3500.

I'm going to check to make sure I can't pull any codes from the car even though the light is off.

 

oil should be change every 3,000 miles unless if you use synthetic , check all spark plugs or the old one they should look rusty brownish color if they are black than you might be burning oil just enough that you don't see itout the tail pipe but you do in the emmisions .. could be cheap gas too .. check your plugs they speak if you know how to read them !!o2 sensors could be bad but not enough to throw codes but bad enough that is running rich !! hope this helps !!

 

I had a Honda Civic that would burn a quart of oil every 100 miles and it would still pass emissions. I am thinking about replacing the 02 sensors. I did have a code for the front sensor a month ago but that was when the fuel injector died and the car was running on 5 cylinders. I might take out a plug too and just take a glance at it.

 

So I just went and checked to see if the car had any codes even though the light wasn't on. And I indeed got a code. 0806 and according to pmohr's decoder for a 1995 is fuel system malfunction(left bank). This would explain the HC and CO% being really high.

One thing I have noticed with my car is I believe the factory y-pipe needs to be replaced. The stock flex pipe is rattling and I believe there might be a small exhaust leak. Could this cause the car to run rich? Or maybe it sounds like the front O2 sensor might be on its way out?

 

Posted an update on the first thread. Any ideas? Maybe run some seafoam thru the car? last I did was 2 years ago.

 

how long did u drive the car before u brought it back...prolly should wait a lil while longer and some fuel injection cleaner....might have to complete a EGR tube cleanin procedure.

 

Car was definitely warmed up. I drove it for 20 mins including some WOT shifting thru the gears. I thought high NOx was a tale tale sign that something was not right with EGR, not high CO%.

 

oh 20 mins man....might take 200 miles. I jus failed my inspection cuz i had to replace some sensor wiring and i took the car in before the sensors had a chance to adjust. THe report came back as SENSORS NOT READY. my mech sd drive it at least 50 miles then bring it back. I kno its fixed cuz when i bought the car the light came on and then the code was cleared. After clearing the code, i drove the car back to my home town and the light came back on in before i was even halfway there. Its like 40 miles to my home town. Give the sensors time to adjust man...if that dont work take it to someone else how wont hook it to the computer. Thats what i shd have done in the first place hehe.

 

whenever u burning fossil fuel, u get NOx. CO, HC and unburned carbon. The EGR lines may have unburned carbon buildup or the fuel filter man or the catalytic converter

 

What year is your car? You are talkin about OBD-II cars (96 and newer) where they just plug the computer up to your car. OBD-II cars have to go thru a drive cycle before they are ready to be tested. My car is a 95 where they have to put the car on the rollers and stick the sniffer up the tailpipe. So the sensors not being ready doesn't apply in this case.

 

yeah yeah I kno what u talkin bout.

I had a problem with emissons on another car. compression was off in one of the cylinders and emissions was horrible.

In your case, the readings got better with the Sensor replacements, but u still got a slient code for fuel injection, which prolly means u not burnin the right fuel mixture in that cylinder. Hmmm, u changed the plugs right? Silly question but u sure u put spark plugs in right w/ correct gaps.

But driving the car a lil more will give it more time to adjust.

 

Inspection station didnt tell what was wrong with it. If it doesnt pass, in my state, they tell u why and ask if u want them to fix

 

I'm pretty sure the compression is good cause the car has great power. They compression being down in one cylinder would effect the power. Yeah, plugs were changed probably 15-20K miles ago. I still need to pull one out and look at them. I did have a fuel injector die on my a month ago and I replaced it with a used one. Maybe the injector was dirty?

In Georgia, we just have emissions. No inspection. So the emissions places just do emission testing. They don't work on cars. They just give you a brochure with places that can work on cars needing emissions work done.

 

What would it hurt to change the oil, it's due anyway. When you think about it, a bad injector could cause excess fuel to get in the oil, therefore you could get high hydrocarbon readings. Just google emissions and your results (whatever the high readings were) and you will get suggestions. If you go to emission inspections with new spark plugs and fresh oil and it fails then it is something else. Wouldn't hurt to do those 2 first since they are fairly simple. I'm just saying mine failed once, changed the plugs, still failed, changed the oil, passed.