Running rich after header install?

**jb'sWS6** · 11-10-2006, 10:25 AM

I have read on other threads that my car should run rich after installing LTs and ORY. I haven't done this yet but I am wondering why this would be. It was my understanding that the original factory tune had the cars running rich to begin with to lessen the chance of detonation in case of low octane fuel. I would think that by freeing up the exhaust by adding LTs and ORY would put the factory tune closer on A/F ratio instead of worse. Am I missing something? I want to get a tune anyway but was wondering.

**BlackLT1Z28** · 11-10-2006, 02:41 PM

The reason you will run rich is because there is less backpressure in the engine. Less backpressure means that the engine doesn't have to work as hard to pump air and force the piston down. Since you don't need as much fuel to burn in the engine, the factory tune will make your engine run a bit rich.

**Mr. Luos** · 11-10-2006, 02:53 PM

Also has to do with the location change of the O2's.

**BlackLT1Z28** · 11-10-2006, 03:26 PM

Originally Posted by Mr. Luos

Also has to do with the location change of the O2's.

Did not know that...

**jb'sWS6** · 11-10-2006, 06:40 PM

Thanks for the info. One last question, will it hurt anything to drive it to the tuner? I plan on installing them myself and the tuner I want to go to is about 1 1/2 to 2 hours away. Plan on eliminating AIR, EGR and cats all at once so I know I'll have SES light but will it be in any kind of "limp" mode?

**Mr. Luos** · 11-10-2006, 07:28 PM

When I got longtubes, I never got tuned.
I raced it several times. It won't go so rich it harms anything...it just won't pick up optimal power.

No 'limp' mode. You will be fine.

**BlackLT1Z28** · 11-10-2006, 07:43 PM

Yeah, I've had my LT's on for a few months now and no tune. She runs fine, except for an EGR related exhaust leak. It doesn't even seem to be running that rich. What are some of the symptoms of running rich anyways? I don't think mine is running rich at all.

**Mr. Luos** · 11-10-2006, 07:46 PM

You can normally smell it. More when it is standing still.
Little extra smoke when WOT as well.

**BlackLT1Z28** · 11-11-2006, 09:51 AM

Well, I haven't smelled anything yet and neither has anyone else (at least, no one has told me) and no noticeable smoke. Would it have been possible for the computer to reset itself to a really damn good setting where the engine takes good advantage of the LT's and adjusted itself appropriately?

**shabysurf** · 11-11-2006, 10:47 PM

Your computer will naturally adjust itself (to an extent) over time, but if you disconnect and reconnect a battery terminal, it resets the computer, and will help level your a/f ratio out faster, but a tune is def. worth it and will help alot!