2FASTBROZ28

I know this has been discussed before but nothing really goes with mine. I just installed lt headers and egr block off plates, but haven't capped the egr valve yet.( am tomorrow) alright this is what's happening, anytime I'm in od about 2500 rpm my car starts to sputter.. I'm checking all my plugs and wires making sure they are good. Anytime I go through my gears though, it is fine. But when on the highway doing about 75 (2600 rpm) and try dropping it a gear or accelerate it starts acting up and starts sputtering.. Before doing the headers it would run perfectly fine, no problems. I'm really thinking its the egr valve since it has not been capped.. Only the header and the intake manifold.. Any suggestions?

Thanks in advance,
Graeson

97z28k&N

You may have burned a spark plug wire on the headers.

2FASTBROZ28

I'll deff check it tomorrow after school.. If that's it I already have new wires.. I'm gonna get codes checked too since its thrown those but I pretty much know what they are

whitdog54

its probably running like crap because of the longtubes and no egr. Gonna need a re-tune asap.

2FASTBROZ28

I know I'm gonna need a tune. I just wanna make sure and get others opinions.. So It's probably cause I need a tune though?

bobdec

If you capped the exhaust tube port to the intake there should be no problem as the EGR valve is opening, but the exhaust input is blocked so nothing happens. You may get an EGR DTC sometimes (about 25% of the time) plus the timing is altered (advanced a couple of degrees) when the PCM thinks it's activating EGR. Better to tune it out , but it will not cause the problems you are experiencing. With your mods you probably already have a tune, but just adding headers is really no big thing, the PCM sees more air flow and adds more fuel and all s/b OK. My guess is a HV spark problem as mentioned previously. How did you extend the O2 harness, hopefully you did not cut the O2 side of the wires, that will mess them up .

2FASTBROZ28

Sadly I did splice them but far back.. Could it be the o2s that are causing what I've mentioned? If so, I do have some others.
I'm gonna check all the wires and plugs as well today.

2FASTBROZ28

New update. O2 are off the check list. The codes I'm pulling are egr of course, evap that shouldn't deal with the problem and maf which is a biggie

Injuneer

I see you have a 97. With OBD-II you are very likely to get the code for no EGR flow. It's OBD-I that is not as likely. I'm assuming when you say you haven't capped off the EGR valve that you also haven't removed the valve. Just adding long tubes and deleting the EGR will not make it "run like crap", at least from my experience.

I'll vote for a burned plug wire or a cracked spark plug porcelain. Are your headers cera-metallic coated (e.g. - Jet Hot?). Seems like a new set of coated headers will often screw up the O2 sensors.

Which MAF code?

2FASTBROZ28

Yeah they are ceramic coating. And it's throwing p0100.. I'm checking all wires here when the motor cools and plugs

Injuneer

P0100 is often due to a broken pink power supply wire in the harness to the MAF sensor. I don't know why the 97 is different, but it's a fairly common problem. With the key on (engine on or off) probe the voltage between the pink wire and the black/white wire at the MAF harness connector. Should get 12V.

2FASTBROZ28

Well I jus tightened 3 loose plugs.. Idk how they can loose cause I made sure they were tight but I was mistaken. Solved the problem though with the sputtering. But I'm gonna get the maf check to make sure it's running properly.

Thanks for everyones input, truely thankful.

2FASTBROZ28

Started sputtering again.. Most likely the maf..

2FASTBROZ28

Update: checked both and pink had 0 v. And the yellow had 5v I blew a fuse.. Change it and checked again. Only running 5 v and the setting was on dc. Still sputters. I'm not throwing a code for miss fire but going to replace wires and plugs? Maybe just old wires?..

Injuneer

If you didn't get 12V between the pink wire and the black/white wire, probe between the pink wire and a known chassis ground.

If you still don't get 12V in the pink wire, pink wire is dead.

5V on the yellow wire, key off is correct.

What fuse did you blow?