Recently bought an 01 s2k and i noticed that it was running rich..
So rich that there is a large amount of carbon build up on the rear bumper and the car is GPW so thats great.
Anyway my dad thinks there could have been a tune on the car and the air to fuel ratio is all screwed because of that.
The car does have a test pipe and I put a new 02' sensor about a month ago.
Any suggestions are appreciated.
Thanks,
Ryan

 

Test Pipe is the reason for the soot buildup, as well as burnt oil leaving soot on the bumper/exhaust.

You can replace the testpipe with the oem cat, or you can live with it.

It's also worth mentioning that the test pipe is federally illegal in terms of emissions. Local and state authorities differ so you might not have any trouble with it.

Look up how to reset your ECU, the car will relearn and readjust, so it might help a little bit.

 

Yeah its definitely your test pipe. If the black soot bothers you, every time you wash the car get some polish and work it out.

 

Car also seems to burn more than the usual amount of oil and occasionally i see blue smoke coming out on my exhaust.

My initial thought is piston rings because of the blue color, any possibility the test pipe is causing the smoke too?

 

I do see blue smoke coming out of my exhaust, but only when I'm in VTEC. Inspect your PCV valve. Do a full compression test to ensure the engine is okay (for me, I use about a quart of oil every 800-1000 miles, depending on how I drive).

Also, the test pipe isn't the fault for any smoke. However, if you retain your OEM cat, it tends to catch some of the oil that's being burnt. That being said, I'd rather clean my bumper more often than deal with risking cat failure because of all the oil being burnt. A cat is more expensive to replace.

 

I do see blue smoke coming out of my exhaust, but only when I'm in VTEC. Inspect your PCV valve. Do a full compression test to ensure the engine is okay (for me, I use about a quart of oil every 800-1000 miles, depending on how I drive).
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Replaced the PCV valve about 3 weeks ago.
Have not done a compression test on the motor but will, if the rings are bad then would you see a drastic drop in the compression numbers?

 

Just another ap1 burning oil. Mine is the same way. Black bumper from test pipe. I've tried and tried to fix the oil consumption issue and after reading over and over about it, I just plan to learn to deal with it until I do a ap2 swap. The issue is the cylinder walls. I've changed everything in the head to oem, changed to different oils from syn to conventional back to syn and still burns. Changed pcv to oem and put a catch can and still get oil burning. Just learning to live with it. Btw compression is 235 psi all 4 cylinders

 

Couldn't have said it any better. Everything is normal, and exactly the reason I went back to the stock cat from my test pipe.

 

That model year S2000 runs pig rich, most rich of any S2000 that was produced. You an actually make a bit of power leaning out the fuel mixture, so I wouldn't expect a tune to be responsible for your issues. You would definitely see a tuning device on your car if someone went that route as it would be a pretty conspicuous device on an ap1.

 

Did the valve stem seals help at all? How did the old ones look?