Well my longtube header install is now entering over one week. Well not the install itself but trying to get the car running good afterwords anyways. The fricken car runs like crap now and I CAN NOT figure it out. I have pulled all the wires I have made sure there all in the right spot I made sure all the plugs were seated well I made sure the wires are seated well on the opti and the thing just misses and I am starting to get very agitated. I am out of ideas and I have no idea what else to do at this point.

 

go over very slowly and dont get frustrated and skip anything...

check that each wire from the opti runs to the correct plug... make sure each wire is on the plug all the way, make sure each plug is in correctly and has the correct gap... check the o2 sensors, check for burnt wires and make sure non are arching....

take it slow and relax...

 

figure out which cylinder is misfiring...or cylinders

there is a possiblity you have a bad wire or a bad plug if it is always ONE cylinder

 

I have made sure all wires goto the correct spot. The plugs a ngk tr55 gapped at .050 which is correct?
I went and got the car scanned and this is what came up

po100-MAF circuit malfunction
po140- o2 sensor no activity detected (bank 1 sensor 2)
po154- o2 sensor no activity detected (bank 2 sensor 1)
po160-o2 sensor no activity detected (bank 2 sensor 2)
po300- random cylinder misfire
po400- egr no flow

now the maf connector was off a little bit and I connected it better but I have also driven the car a while and wouldn;t the code have cleared?

I don;t have the rear o2 sensors connected right now so that accounts for the 140 and 160

The egr has been removed and blocked off so thats 400

now would the o2 sensor code cause the random misfire to occur or no?

 

I did find one burnt wire and replaced it but the car still runs like crap.

 

umm...maybe false knock... do you have the lt4 knock module... the headers could cause this, but i dont know for sure... i would suggest plugging in the o2's, and putting in the knock module and then see

 

could I disconnect the knock sensor and run it would that eliminate the knock sensor possibility?

 

Try this...

Unplug 1 O2 sensor and then reset your computer pulling the PCM fuse in the fuse box located on the drivers dash side. Pulling the fuse will clear all the codes... unplugging the O2 sensor will keep the car in open loop so they dont function. With that variable out of the way you can focus your attention on plugs/wires/MAF. If the MAF sensor cuts in and out the car will run aweful because I had the same problem before. If you are sure the MAF isnt acting up then the only thing left is plugs/wires. You said you made sure the plugs were tight but didnt mention anything about replacing them so try some new plugs... they are cheap. Good luck

 

I dunno if this would involve you case or not but the O2 wires run really close to the right side primary. Maybe thats the reason why you're pcm isn't picking any signal from the O2's. You might have burnt the wires that run to the pcm. Hope this helps.

Mike

 

Crap from your new header's blew down and trashed your O2 sensors.Especially if they were coated.After header install the O2's should be left out for a couple of heat cycles before you drive it.
With the bad O2 the engine can't tell what fuel to put in.

 

One code is telling you that bank 2, sensor 1 is not working.

1racerdude is correct that it has been suggested that the "burning in" process of new headers will ruin O2s. It has been discussed many times on this board.

 

make sure the tops on those TR55 plugs are screwed on all the way.. I hate those plugs.. i use auto lite 106 plugs.. NGKs are great, i just dont like em.. Is your MAF hooked up? No one said anything about the MAF circuit malfunction.