IM going crazy , well first off about a week me and a buddy installed my longtubes did not seal the egr flange on the passenger header because was going to do the egr mod,I ran open headers for a couple days ,then decided to have a exhaust place to weld some straight pipes on so my O2 's would not go crazy... well ever since i started the car up with the headers and about 5 mins after that my ses light would go on, then off when i come to a red light.... and also have noticed i have a slight miss through the whole rpm power band , not quite a sparkplug miss but iono, well before the headers and the ses light me and buddye tested my car right before the install, and aas usual we were dead even from a 2o roll up doesnt matter what mph we start always the same,so we decided to test the cars out tonight
we both hit it he instantly pulls 2 cars and keeps pulling within like 2 seconds , we did it again same results. I have lost horsepower its killing me , there is a couple thing ive got to the car , i got emisson long tubes but did air and egr , capped up the spot were the egr was with a block off plate and capped up where the vaccum egr hose was, but still didnt seal the hole on the header where the egr tube is supposed to connect to the header, and the air pump fittings also have a leak.next is i think MY O2s are trashed i guess thats why I get the ses light,Would I
having bad O2s and the header leaks would cause my car to lose so much power? i checked my plug wires they seemed fine btw... please help

 

Triple check your plug wires...They may look ok, but still be burnt. The car will feel like it's running rough if a wire is burnt, and feel really slow compared to what it should. And it's also possible you messed up the O2s running open headers, your plugs might be all fouled up. I'd check the wires 1st, make sure there are absolutely no burn marks at all.

 

I am having the same problems although i have lost about 100hp

 

ok if its a O2 problem can i jus unplug them will that solve anything?

 

No that will make it really run like crap,make sure you have no exhaust leaks the knock sensor will pick that up and pull timing.Plug all your open holes in the header im sure that is 50% of your problems .You may have to replace both of the o2 sensors if they have become damaged,did you have to extend the o2 sensors wire? if not connected correctly it will not run right also check for burned o2 wires on the passenger side next to the header,the factory harness runs awfull close to the header there on the fender well.

 

NO, this will put the ecm into limp mode. replace the o2's and seal off all of the air leaks, as this will give the o2s a bad reading.

 

I'm planning on those PACESETTER's someone help them out. Idon't want to get stuck with that powerloss..................

 

My .02

Do you know what code the SES light is tripping on? That may lead you in the right direction.

 

Well im going to go check for Arching in a few mins then tommorow go and seal all the holes in the header,check all plug wires for burns ,check O2 sensor wiring , then buy them D@mn expensive O2 sensors I guess, am i missing nething?

 

Nope autozone will not scan the car because Obd1 , i dont know of anybody that has a obd1 scanner, and my gm dealership will charge me outrageous for a scan, but this happened with a header install so i think my O2's are shot there original ones
car has over 100k btw , need to be changed neways

 

Nope im sure it will run better for you especially if it ran fine before the install good luck!

 

Check the plug wires for pin holes as well.

Burns are bad news obviously, but a small pin hole is enough to arch to a header instead of through a plug. I've seen a couple bad wires that looked totally fine but under current they arched like crazy... closer inspection showed a tiny pin hole where the arching was happening. If it's high-temp silicone the arch many not burn anything enough to tell, and if it s rubber, well... it's already black.

Good luck man, let us know what you find.


P.S.
I'm suprised the title didn't prompt another shortie vs. LT discusssion.

 

Yea, thanks man it feels like when i put the headers on, that i dropped a V6 in too lol.it sucks spending money to go slower

 

Don't you need an inexpensive tester for OBD1?

 

My mistake. Thinking of 93's.