Nearly Stock KA didn't pass smog...ideas?

[Jimmyg41]

Well it was smog time and I failed pretty miserably. I got 5.0something on the Co2 part which you're only allowed to get a 1.0 on. I reset my ecu to take off the check engine light but before it was throwing a code that said I had a bad front o2 sensor. I told the guy at the smog place and he said that was a problem but wasn't the whole problem. I also thought that maybe my cat was done for or something but does anyone else have any ideas? I have a 95' 240 and it does have some miles on it, about 136k to be exact but no real problems. I do have crappy gas mileage and a rather erratic idle. Any help would be cool...thanks.

[Buffalo Daughter]

buy a new o2 censor since its shooting that code off. Second if you think the cat is burnt out and does not work anymore you can A) keep it and gut it and use it as a straight pipe while you buy another new cat or B) buy another cat but yeah definetly buy a cat while your getting a new o2 sensor.

www.pdm-racing.com has the stuff you need. Also check if you need a tune up , you know clean filter,new oil,new plugs, wires etc etc.

Other than that reseting the ecu doesnt actually help cause the codes will show up again. The irratic idling btw has to do with many things one being the o2 sensor.

So do some research about the sensors and smog and you should be alright.

[Ritz S14]

Yeah.. he's pretty much right^ most common cause of high CO failures is due to a malfunctioning oxygen sensor. I bought my 95 with 149k, bone stock.. passed with flying colors. But yeah, try changing the o2 sensor, before you replace the cat.

[Pacman]

If you get a new cat while its running rich you'll burn your cat an it will be useless. Get a new O2 sensor and pre-test it.

[DogFather]

All i did to pass mine was bypass the hoses on my EGR valve and it worked like a charm. Just make sure the smog people would not see that bypass.

[ghostuss]

if my engine is throwing a EGR code. can I just plug up the EGR pipe and reset the ECU to pass smog?

[Ritz S14]

^ Sure, if you do that you'll probably be labled as a "gross polluter".

Th EGR is an emission device, so whenever you alter it.. most likely you'll fail miserably.

[Blues13]

The O2 will help a lot. That explains your bad gas mileage and rough idle. It's prob running too rich because of the bad O2.

[idlafie]

Originally Posted by Jimmyg41

Well it was smog time and I failed pretty miserably. I got 5.0something on the Co2 part which you're only allowed to get a 1.0 on. I reset my ecu to take off the check engine light but before it was throwing a code that said I had a bad front o2 sensor. I told the guy at the smog place and he said that was a problem but wasn't the whole problem. I also thought that maybe my cat was done for or something but does anyone else have any ideas? I have a 95' 240 and it does have some miles on it, about 136k to be exact but no real problems. I do have crappy gas mileage and a rather erratic idle. Any help would be cool...thanks.

Jimmy,
If you can take a picture of your smog report & post it here so we can take a look at your readings & help you narrow down your problem.

Prior to taking your car into getting it smog checked, you should have done the following, (it's too late now, but it still might help): Change the air filter, fuel filter, sparkplugs, distributor cap & rotor. Flush the throttle body with carburator cleaner & pour a can of fuel injector cleaner in the gas tank. Also flush out the PCV valve with carb cleaner also. Check the Engine Coolant Temperature Sensor along with the Oxygen sensor. Check your Idle with the throttle position sensor harness connector disconnected? (it's a 3 wire subharness next to the intake manifold..the wires should be black, white & green (??..not sure). Is it at 650 rpm +/- 50 rpm? How bout your timing? Is it at 20 degrees??Also, did you check the vacuum lines running to the EGR system??
All these factors play a key role in your car passing smog. A bad Oxygen sensor can cause excess gas to be dumped into the intake manifold, but a faulty Engine Coolant Temperature Sensor can also be dumping more fuel into the throttle body than it should be. A bad signal from the E.C.T.S makes the ECU think your car is still cold, and as a result the ECU dumps more fuel into the intake. If your engine timing is off, that would also cause you to burn gas. A lot of things to consider.

Anyhow, if you want to better understand the numbers on your Smog Check Report, click on the attached link...it explains everything in plain engrish...
http://159.145.15.175/StdPage.asp?Bo...y-May_1996.htm

Anyhow, good luck with the repair...if you need anymore info, feel free to ask. Hope this helps...
ID
'95 SE who's failed smog twice!! Fixed the problems & got it to pass...

[idlafie]

Originally Posted by ghostuss

if my engine is throwing a EGR code. can I just plug up the EGR pipe and reset the ECU to pass smog?

Check the vacuum line running from the secondary BPT Valve to the EGR. That rubber vacuum line has a tendency to crack / melt / split / break. When that happens you lose vacuum to the EGR system causing the ECU to kick a code.
You could also have carbon buildup in the EGR valve itself. Easiest way to clean it is to spray car cleaner into the top tube of the EGR valve & move the underneath diaphram portion of the valve up & down with your fingertips as you spray carb cleaner into the top tube of the EGR valve. This helps to remove any carbon buildup you have in the EGR valve.

If after doing all this, and your ECU still kicks a EGR code, then go back and check all the vacuum lines running to the intake & carbon cannister for a line that may be disconnected, cracked/split/melted or just clogged.

Anyhow, hope this helps..good luck!!

ID
'95 SE

[Jimmyg41]

Thanks Idlafie and everyone else who posted. I'm gonna go try and see what's up with my car today since I finally have time off. I'm determined to pass smog....I have a new cat and o2 sensor...we'll see.

[Ghettokracker71]

That sucks you didn't pass ,dude. I'm glad I don't live in a smogged place,otherwise I'd be screwed !

[96twofourty]

Originally Posted by Buffalo Daughter

buy a new o2 censor since its shooting that code off. Second if you think the cat is burnt out and does not work anymore you can A) keep it and gut it and use it as a straight pipe while you buy another new cat or

.

how would this help in passing smog?

[HyperTek]

run some seafoam!!! helped me out tons

[Jimmyg41]

Sorry guys...I know you were anxiously awaiting a response. I did pass smog.

[mxexux]

DUDE...Thanks so much! You had me in suspense for 8 years.