Failed smog, did some tuning up, have some questions.

[87e30]

Well I failed smog a couple days ago.

I've had the car for like 8 months and know for a fact in the past year it hasn't been tuned up. Shame on me I know but it's a damn eta. So failing smog wasn't too surprisng.

I was getting 21mpg mixed driving styles and mixed highway/street.

I replaced with OEM parts cap/rotor, spark plugs, cleaned K&N filter, and did an oil change. Now I get 22mpg.

Anyways, I'm thinking if I fail again I'll try replacing the o2 sensor and maybe the cat.

REAL QUESTION BELOW:
When I got the car it had a vaccuum leak (duct taped intake hose). I finally got a new one about a month ago and now the car idles way smoother. However it idles at like 1200 rpm or so. When I start it the idle will fall to maybe 800 rpm or 900rpm but once you start driving the idle returns to 1200 rpm. I figure this has to be hurting my idle results for emissions.

Where do I start with the idle problem? I have a hunch that the idle was manually raised before to compensate for the vac leak but I don't want to assume this right away if this is an indication of a bad part.

[jlevie]

A high idle on an ETA could be intake leaks, a sticky or bad ICV, mis-adjusted or bad TPS, mis-adjusted throttle stop, sticky throttle body or throttle cable, or a bad idle control module. Fixing this is a matter of eliminating suspects. The definitive diagnostic for intake leaks is to have a smoke test run on the intake.

The useful life of an O2 sensor is not more than 100k miles. If that applies, it needs to be replaced. And on a car of this age, new ignition wires are almost certainly needed.

[87e30]

What is the likelyhood that the high idle would hurt my emissions?

I'm mostly looking for ways to pass emissions as I don't want to throw more than I already have (200 dollars) at this stupid m20b27...

Wires are expensive but yes I could probably use them.

[netcsk]

How did you fail emissions?
That can help diagnose.

[87e30]

This is everything that's relavent I belive. Thank you for any help. Trying to not replace EVERYTHING too by the way. Note first post.

[joshanoya]

i was looking at your table and this might help you...

http://www.smogsearch.com/index.php?page=faq

[jlevie]

The O2 sensor is probably bad (considering its probable age) and is a contributor, but I don't think it fully explains the results. The engine is running rich, or having partial misfires, or the catalytic converter is bad. Or perhaps all three.

[87e30]

The O2 sensor is probably bad (considering its probable age) and is a contributor, but I don't think it fully explains the results. The engine is running rich, or having partial misfires, or the catalytic converter is bad. Or perhaps all three.

Where would you suggest that I start?

I think I may have the car retested since I did do a small tune up and see how the results change, hoping to pass and maybe I'll get some more clues.

running rich/partial misfires is something I have no idea how to diagnose. My only idea is to try a new o2 sensor.

[jlevie]

Unless you are certain that the O2 sensor has well less than 100k on it, replace it. Have the intake smoke tested to check for intake leaks and replace the ignition wires. Verify that the fuel system is operating correctly be checking fuel rail pressure and repair is so indicated. Then have the car re-tested. If it fails replace the catalytic converter.

[ClassicScot]

had same issue with my car after i had head replaced (288 cam) idled at around 900 i bumped the idle up just before the aircare=smog to 1200, passed no problem. I had recently failed on just Idle exactly as your read out says. I would change O2 sensor and bump your idle just to pass, then adress the issue(s) afterwards.

[87e30]

Apparently the guy told me my idle was too high and said to go to a mechanic.

I failed again. This time with results worse than the last ones. What the fuck?

wires and o2 sensor here I come?

[ClassicScot]

i poured 1/4 litre of methyl hydrate into my gas tank when i bumped the idle aswell. I know its not ideal but i did it and passed. Sorry i never mentioned that before im sure there are tons of r3vers who will tell you to not do this. I did it once and with no bad repercussions

[87e30]

i poured 1/4 litre of methyl hydrate into my gas tank when i bumped the idle aswell. I know its not ideal but i did it and passed. Sorry i never mentioned that before im sure there are tons of r3vers who will tell you to not do this. I did it once and with no bad repercussions

Yeah. I think my idle being high isn't helping me though... he said it seems off.

I think I'll try an o2 sensor tomorrow and see what happens.

[e30trooper]

change teh o2, u can get a bosh one for 23 bux cut and splice ur self, spark plugs, run 91 oct. and drive ur car hard b4 teh test, if you fail agian get a Catlitic converter and im sure you will pass unless its your timing

[87e30]

change teh o2, u can get a bosh one for 23 bux cut and splice ur self, spark plugs, run 91 oct. and drive ur car hard b4 teh test, if you fail agian get a Catlitic converter and im sure you will pass unless its your timing

WHAT?! Where can I get one for 23 dollars! I'd order one this moment if I could find that!

I see them for 100+