Thread: header install issues

well like the title says im having some issues after my header install. I bought the ssac headers, had no trouble removing the old manifolds, and all that seeing as the motor was rebuilt not to long ago. The header install went pretty decent and im happy with the fitment. the front 02 clears the firewall great, no issues near the swaybar, and only had to do a little tweaking to get the front off the radiator fan cover. After the install i went for a test drive and im getting sputtering like a miss at anything over 1/2 throttle. Ive checked all over no vaccum lines undone that i can see, i extended the front 02 harness and that seems alright. Im getting a p0300 code with flashing at moderate throttle. The one thing i did notice however is i forgot a bolt from the rear header into the egr tube. would this be something to cause this? Also I left the plug in the rear 02 socket until i can get the old sensor out. if anyone has any thoughts id appreciate it thanks in advance

Another thing i noticed was when i first started to tear into the motor there was a lot of water sitting in the deep parts of the intake manifold, and by the injectors. Ive got the sd hood and its been raining a lot lately, so this could potentially be something but it seems like it wouldve evaporated by now.

As far as the header install, you have a misfire somewhere, and its bad enough that the car is yelling at you when the SES blinks. check all your wires to make sure they are going to the correct cylinder. Also, if the wires are old, then replace them.


As far as the standing water, is it just water, or coolant? Do you have the aluminum gasket? When I had my SD, it did let a decent amount of water into the engine bay. I actually have a set of foam inserts i made to block the heat extractors when the car was just sitting. If you're interested, lemme know, I don't need them anymore.

wires only have about 10k miles on them, i did break one of the plugs in the #1 cylinder but i replaced it with the same plug as all the other cylinders. ill have a look tommorow when its cooled down and double check the wires. and as far as the inserts what are you lookin to get for them? i just bought another dd so i dont rack up the miles and wear and tear on the gp so im interested for sure

I'd put my money on either the wires are on the wrong plugs, or you need new wires.

You have PM about the inserts.

think id be able to run a 105 plug with a homemade intake, headers, and a pcm? i might just do plugs and replace the wires anyways.

Originally Posted by nicks98gtp

The one thing i did notice however is i forgot a bolt from the rear header into the egr tube.

Nick, you mean the tube that is held to the exhaust. This could be a leak, and being before the O2 it will mess with fueling etc.

yeah, is imn gonna do a little more research, but i shouldnt have to do anything special to delete the egr all together right?

Block it off at the header and LIM, remove the code from the pcm and tune for the change in cruise airflow etc when EGR would typically be opening.

FWIW I no longer "make" egr brackets from steel etc with a hole in them for the bolt. I take the pieces off teh EGR tubes and use a dab of rtv, that piece and the bolt that held the piece in place with a penny as a plug in it to block the ports.

awesome. Just trying to clean up the engine bay some more, im gonna go out and grab some new plugs and wires to be safe. What in your opinion would be a good plug to run with setup? you think i can go cooler yet?

well i got it fixed. went a bought a set of 105's and a new set of wires. found the problem when i was taking the old plugs out, number4 had two cracks all the way down the side. gapped the new ones at .50 threw em in and she runs great again.