Running rich on driver side?
 

Okay, all my spark plugs are black on my driver side. The LTs were installed almost 2 months ago without a single problem for a month with driveability until I cleaned my KN filter. Thats when **** hit the fan.

**Here's what happens. I'll start the car and it will run fine for a mile or so then get real choppy and nasty. The SES light will flash for misfire. Then within a few miles it will cycle it self out and run totally fine. Yesterday I had the EGR, AIR, and rear o2s deleted out. On the way home, it started up fine, got choppy, and then cycled itself out again. There were no codes thrown for the opti. **

Here's my checklist, but I need some imput from you guys as well:

1) Install new plugs. Wires are brand new and in the right order. Maf is reading and cleaned.
2) My buddy said to take off the TB and clean it out as well so I will do that.
3) Tighten all the header bolts. Per tuners request. They are snug as a bug.
4) New o2 sensor, the spark plugs are black then it's pretty black I'm sure.
5) The tuner said to weld up the rest of the exhaust. It has the Y-pipe on there, but I don't feel this would cause any of the problems. Like I said above the car ran fine for almost a month without a catback.

Any ideas? Questions, concerns?

IF I got this right, it started this right after you cleaned the K&N air filter. After you clean you have to oil them, right? If there's too much oil in the filter it will restrict air flow. Maybe you should try running the car without he filter for a test drive.

From your description of how it runs, I'm wondering if it's running so bad that the computer goes into open loop and stays there. If the values get too far out of whack, the computers will revert to open loop and use fuel tables to control everything. It's thier way of staying running when they don't know what to do with the inputs they recieve.

You say there weren't any codes for the opti, were there any codes period? We also need to know more about your car. Year,mods,trans...

Exhaust leaks near the O2's can cause a false reading.