Smog problems....DAEDALUS to the rescue?

[dumbusername]

I just bought a 1994 240sx (140,000 miles). It's having some real emission problems. I've read as many of your posts as I could. Man, you are one prolific genius!

I don't have a copy of the first smog as we aborbed it three times. I do remember it was a "Gross Polluter" in HC and CO. After the first fail I had a new O2 sensor installed. The car ran a little rougher and the idle speed droped. Re-pretested. Here is that reading:

15 mph 2192 RPM HC 159(F) CO .61(F) NO 2682(GP)25 mph 880 RPM HC 136(F) CO .59(F) NO 2400(GP)

Next I had the ecu checked it had a code 32. The garage took out the EGK, cleaned it and reinstalled.Here's the re-pretest after that:

15 mph 1703 RPM HC 120(F) CO .54(F) NO 1642 (F)25 mpg 1711 RPM HC 113(F) CO .52(P) NO 1460 (F)

Next I had a new cat installed. The garage said to run it hard this weekend and comeback in for a another test.

This morning I'm driving nice and relaxed and the check engine light flashes again! The idle is low and the car is running rough. I don't know what to do next! HELP!

Thanks! And hey, and we're neighbors! Oh and yes, I know the person I bought the car from is responsible for the smog. But he's goinf to dump it for parts if it won't pass. And I LOVE this car!

[DAEDALUS]

Wow, I don't think I've ever seen anyone fail all 3. It's almost like you're running rich and you're overheating at the same time. I'd pull the spark plugs out. If it's running that bad the plugs should have some clues. Hopefully there's one that looks much different from the others--that'll narrow down the problem to one cylinder at least.I think CA has an exception where if you spend over $400 or something to try to fix the emissions you can get a 1 year relief from the smog requirement. Save your receipts.I never updated my profile. I moved to Hawthorne a little while back. Actually closer to you now than before. Southbay is awesome.

[dumbusername]

Thanks so much for getting back to me! Heres' my update: The seller sent me to a friend's shop and, guess what? I passed! Here are the new numbers:

15 HC 87 (made it by 1) CO .06 NO 13025 HC 51 (made it by 2) CO .06 NO 37

Now, I should be thrilled about that, but I have the feeling that something is fishy. Know what I mean? Could the new cat have made that much of a difference? And this shop also rechecked the ECU and again it read code 32 EGK. The machanic went to take out the EGK but he stopped and called over the owner. They looked at the mechanism and told me that there was no way the this EGK was taken out and cleaned. They said there was NO activity marks on the bolt, there was no sign that it had been removed. So, here I am, not knowing who the hell to trust - or know what is really going on with my engine.

I know I should be doing all this work myself and I'm more than willing to learn. This site is so valuable! I'll never be a mechanic but since I'm able to ask you guys questions and get such great answers, I at least sound like a I know enough to talk to a mechanic! LOL

What I'd like to be able to do is have someone look at the car and be honest with me about what needs to be done and in what order. Then I could see what I can do myself and pay someone to do what I can't. Does that make sense? Anyine here willing to do that?

[DAEDALUS]

The first one was the fishiest. Usually the conditions that create NOx don't create HC and CO, and vice versa. I don't think a cat would make that much of a difference either, but I don't know. Regardless, the car is still not tuned right. You ought to be passing with flying colors. The EGR helps to drop NOx, but usually it's not needed for a smog test. Typically activated when highway cruising or if overheating.

[dumbusername]

Thanks again DAEDLAUS!

I'm really looking forward to driving my "new to me" car with the engine tuned and timed perfectly.

I'm going to call a shop in Torrance that I saw someone on the board recommend. I'm not ready to do my own tuneup yet. But I'm thinking about trying to do the plugs and filters myself. I know this is nothing for you. But trust me, I'll be feeling very accomplished if I manage this on my own!

[Ubernoober]

Do not cross-thread or overtighten the spark plugs. You are screing into aluminum. Use a torque wrench.

I only mention this because it is easy to overtighten spark plugs and once you strip one, you are in trouble.

[dumbusername]

Ubdernoober - thanks for the advice.

I'm hoping to find someone who will walk me through it. You know what they say, tune a friend's car and you've made a dependent pain-in-the ***. Teach a friend to tune their own car and you've made a beer buddy!