Dr. Jeckel

iTrader: (12)

I finished everything up, started right up and it runs perfect. The car doesn't miss or act odd in any way when idling. I started to drive it home and noticed every once in awhile the car would act like someone tapped the brake. I never got on the car or even got it above 2000rpm because i'm a little weary of the exhaust clamps. I plan to take it to my exhaust shop on saturday to have them weld some or all of it up.
Does this sound like something anybody else has experienced before?

The car has been tuned before when the cam and macs were put on, because I took the air system off and no code, so it must have been deleted. The car also has rear O2 sims.

I am going to install my torquer v.2 cam in next week sometime then take it to be dyno tuned, but for right now I need some help/advice to clear my mind or lead me to a solution.

Thanks, James.

Magnet

iTrader: (36)

that doesn't really make sense to me?? just did my header swap last week and nothing like that happened? also i would weld up your exhaust because it will make future mods a PITA. just get some good quality band clamps and torque'm down, nothing to be afraid of....

greysteel_M6

iTrader: (5)

Might be a stupid question, but is this happening while your just cruising or coasting-engine breaking.

Dr. Jeckel

iTrader: (12)

It was just cruising or under slight load.

Need some help guys...

outkast6991

iTrader: (34)

i don't know about a "slight brake feel",but when i picked up my car from the header install it ran fine for about 5 miles.then it started a bogging feeling and alittle sputtering.found the 02's were not plugged in right.just a thought

Dr. Jeckel

iTrader: (12)

On the way to work I concentrated on what it was doing and it is basically missing.
If I try to accelerate faster, it does it worse, it surges and misses.

The O2's are all plugged in properly, I know because I had to unplug and plug them twice to route the wires outta the way of the headers. Does it matter whether you use the back O2's or the front ones? I think I used one of the back O2 sensors on header. Would this cause a problem?

I will try and check the wires again tomorrow, but a rain/snow storm that is moving through is going to make things difficult

BIG_MIKE2005

iTrader: (116)

Man thats sucks. I didn't have any issues with my LT/ORY install. Hell, I even drove mine for about a week or 2 open LT's. Then got the ORY installed & used the supplied band clamps. Still haven't had not one issue.

Did you do plugs & wires at the same time?? Triple check the plug wires & make sure they are all the way on.

RobbieTransAm

iTrader: (4)

Your problem sounds exactly like the ones I had. Did you remove the spark plugs when installing the LTs? After my headers were on I installed my plugs, but ended up having to take the driver's side back off. When putting the header back on, I busted one of the plugs and didn't know it. Car ran like total *** when I tried to accelerate. I change the plugs and wires and fixed the problem. Just a thought.

Dr. Jeckel

iTrader: (12)

Its frustrating. I did plugs(after the headers were in) and the car already had MSD plug wires. I got all the drivers side to "double" click, but a few on the passenger side wouldn't click. I pulled them out and pushed on repeatedly, as far as physically possible, but couldn't feel or hear a click.
I will try and check the plugs and wires again today. I know thats got to be it. Thanks for the help guys.
Another one of those great car modding things

erikthegoalie

iTrader: (29)

sounds like a tuning issue, that brake feeling you feel could be attributed to the richness at which your engine is running now...its just "sputtering"

get a tune, if it continues then continuie narrowing it down

Dr. Jeckel

iTrader: (12)

like I said, I am fixing to install my cam, then get a tune. The car had mac's and oryp before and a tune, so i doubt it would change this much. I'll check the plugs and wires again.

Also anyone know if the front and back O2's are interchangable?

brad8266

iTrader: (23)

There is no possible way that the car is running rich to cause problems like that. The O2 sensors will handle fueling corrections during normal driving so you will stay at or very close to stoich. Why does everyone spout out this misinformation that cars run rich, even in closed loop, after header installs? It isnt true, its just an Internet myth that people have picked up on and just repeat without knowing.

You probably cracked a plug or something, i did the same thing, had a tiny hairline crack in one plug.

You should go back and check everything over again, plugs, wires, electrical connections, and make sure everything is tight and sealed up.

brad8266

iTrader: (23)

Yeah they interchangable. You say you had a tune before, so do you know if the deleted the codes for the rear O2 sensors? If so the sensors could also be bad and the PCm is not reporting a code. I would have thrown a fresh set in during the install anyway.

Dr. Jeckel

iTrader: (12)

I bought the car from a dealer and it already had a small cam and the headers and oryp. The O2 sims were also on the car and the rear O2's wear still in the exhaust though. I believe it might be a cracked plug because I was tightening one down and heard a crack. I pulled the plug back out and no crack in the porcelin, but it might be the problem.

Can you get the O2's at an autoparts store or just at the dealer?

Thanks for the help.

brad8266

iTrader: (23)

You can crack a plug with a crack so small that you can barely see it.

You can get O2's at autozone or any other parts store. It will cost around $150 for 2 of them.

Dr. Jeckel

iTrader: (12)

ouch...i'll try the $1.35 plug first

brad8266

iTrader: (23)

Yeah good idea.

erikthegoalie

iTrader: (29)

thats not what my tuner told me about my car..but ok...I am not saying that its like off the charts, but these cars are not tuned for headers...so, when you install them, things will change(havent people screwed up o2 sensors after header installs if they dont get a tune right away?), look at the new part to be the source of a problem first...then work you're way through...misinformation? dont get your panties in a bunch dude, get back to work...

brad8266

iTrader: (23)

Well good for what your tuner says because it isnt true. Who is your tuner if you dont mind saying?

When you install a set of headers you are increasing airflow through the engine. This increase requires the addition of some fuel in order to maintain stoich AFR (14.7). Without a tune the PCM will be using the same airflow values as before the header install which would result in a lean mixture, but the PCM uses the O2 sensors to provide fueling correction (LTFT's) while at idle and part throttle operation. So at idle or part throttle the O2 sensors will give feedback and the PCM will adjust fueling accordingly and continously. That is why the signal from an O2 sensor is a sine wave, it is always switching back and forth. I went over a year after installing headers before I tuned my car and I never had a single code thrown or any other issue.

The main issue with headers is that sometimes due to the changing of the distance of the O2 sensor to the engine it creates an o2 switching problem.

The only reason my panties would get in a bunch is because instead of helping the guy you gave him bad information. You told him to go waste 500$ on a tune first before doing good troubleshooting when it is completely not needed. Dont give advice on something you dont have direct knowledge of.

BIG_MIKE2005

iTrader: (116)

I know my car required no tune after the LT's. Still have no tune, just got my codes deleted. And, no one else I know personally with a f-body has had to have a tune for LT's either. I think its more hype & of coarse your gonna get more of a gain if you go out & spend the money on a tune just b/c of LT's. The tune itself w/o the LT's would net you a gain.

Hell I dropped from a 13.4 @ 104 to a 12.9 @ 109 with just the addition of my LT's/ORY combo & LS7 clutch. And yes thats without a tune & my O2's are still switching perfectly with 90k on them. When my tuner hooked up to mine to delete the codes he showed me everything he could & let me watch my O2's switch. My a/f was perfect & I have never had not one issue. I drive my car about 75 miles a day at least in stop & go traffic & highway driving.

If a tune was required, I would surely know by now.