What are my options when installing Pacesetter LTs in order to NOT have a check engine light on all the time. the headers are emissions legal WITH AIR and EGR tubes built on. No Cats. race only y-pipe.

The drilled o2 bungs in the header collector are for the Pre-Cat o2 sensors (and i have the o2 extensions)... but where do the Post-Cat o2 sensors go? am i lookin at O2 simulators to fix this?

i just passed emissions testing a few months ago... they didnt hookup any sniffer test but only LOOKED for a check engine light. i asked while i was there and the guy said "As long as you dont have a check engine light on, you'll be fine because you have a 97 OBDII" ...I live in Maryland

If in the future if i MUST have cats i'll just put on a custom Y-pipe with built in cats. in a year or so..

Am I correct in all my info so far?

thanks in advance!

 

The only way you could incorporate post cat 02 sensors is if you had a catted y-pipe and additional 02 bungs after the cats. So yes, you are correct that you either need 02 simulators or just have the code programmed out of your PCM.

 

I'm just gonna leave the post-cat o2 sensor to just dangle outside the y-pipe so it will atleast get some type of reading to the ECM, untill i can get it programed out of the comp or get an o2 sensor.

is this gonna make my car run like crap untill i can get a fix???
or should it be disconnected altogether??

 

Its going to be of little use just dangling around, I would just take it off until you get the simulators. And to answer your question, unplugging or removing the rear 02s will not effect the driveability of your car. Their job is to simply monitor the efficiency of the catalytic converters.

 

if you let it dangle it will throw a code. get o2 sims. once and a while you will throw a service light because of the free flowing exhaust and the egr can't do its job properly.

 

02 simulators or get it tuned out.

 

I pulled my rear o2's out when i did my LT install, and havn't got sims or had the code tuned out yet, hasn't affected anything other than throwing lots of codes

 

right now im driving around with NO O2 sensors at all and the car runs like CRAP!!! i bought a set of Denzo sensors for the front and am waiting for a set of o2 sims to come from summitracing for the rear. (i have old spark plugs plugging the o2 sensor holes)

how long should i wait for the junk to burn off before i put in my front o2s? i have about 30 miles since the install. they are pretty expensive and i dont want to risk ruining them.

the car runs like crap popping and sputtering all over the place with no power. hopefully the new o2s and sim will fix this correct???

 

You're running NO oxygen sensors? Front O2s are an absolute necessity for the PCM to know how much fuel to use.

 

Well upon that response i put my old o2 sensors in with extensions, and reset the computer. I figure i can ruin these ones at 90k they were prolly ready to go anyway.
Now,,, there is no check engine light, which good i guess even though there are no rear o2s or anything. but the car still runs like junk.

up to 1/2 throttle it runs good through all rpm and sounds nice too. but anything after half gas it'll start sputtering and popping with almost no acceleration.

all this excitement for long tubes and now it runs like crap!!

but all the info has been great so far thanks!! please KEEP IT COMMING!

 

That's strange with no codes. My 96 SS has several codes and it's running great since the header install. I think I have an EGR going bad which is causing a couple of codes and the old O2 threw a code so I'm glad I didn't put new ones in yet. Almost sounds like something is still disconnected or loose. Did you check to make sure no wires got cooked and that your plug wires aren't arcing or getting cooked?

 

UPDATE: after rewiring all the plugwires and triple checking everything...i started it up and it purrrrrred, well actually roared!!!! runs smooth and POWERFULL!!

check engine light is still on but should go away after new o2s and sims. hopefully.

im going to drive around for another day to make sure all is burned off before installing the new o2s. at about 7-9 mpg i cant really afford to drive much longer before putting them in.

thanks to everyone who helped out on the forum

next project...http://www.dynotech-eng.com/dynaspark.htm
Dynaspark opti replacement. which by the way the company has been sold. so maybe the prices will go down????

 

update:

The car started bucking and popping again during acceleration a few days ago.
So I replaced the Emissions tube that runs under the TB because I knew it was causing problems. The car smelled like a go-cart track of gas vapors every time i got out. ANYWAYS it didn't fix the studdering, instead I found plugwires 5 and 7 were toasted from the LTs. Replaced them with my old 5 and 7 stock wires(80k miles old). That fixed the studder/popping.

My current problem is really stumping me out and it DIDN'T do this before the LTs went in...During Wide Open Throttle, the engine will vibrate insanely fast with a serious power loss. But 1/2 throttle the car will pull hard and smooth all the way to redline. All my plugwires are in good shape, ziptied away from the LTs. Only happens at WOT and when the car has warmed up slightly
I had the car scanned and NO CODES what so ever.

The coil is brand new ACdelco replacement. (I did the ICM/coil spacer mod and it didn't help) and i doubt it's the opti. it's definatly ignition related because the car didn't do this before the LTs.
Can this be cross spark from ziptied wires?
hellllp before i run this thing into a lake