[Letchworth40]

I spent all my money on longtubes and a catless midpipe and was wondering if I need a tune so the Service light wont turn on. I know I need a tune for the best gains but I was planning on getting that in a few weeks when I free up some more $. Should I wait for the install or not.

Thanks!

 

[Go Bucks!]

I had my LT's on for a couple weeks before I got my tune. You'll get the check engine light (as I did) but the car didn't run bad or anything. You'll definately want the tune, but you'll be fine w/out it for awhile.

 

[LS2BlueGoat]

I would personally wait to install them until you can get a tune right away. I am sure you will get responses from people saying go ahead and install but I always go on the side of caution.. It's not like you won't be able to drive it though if you do, you just won't see the full poetential. It if it is only a couple weeks I would get it all done at once. You will throw codes though at the beginning but they can be deleted

 

[LFSADRG]

I did not get a check engine light. The car ran fine.

A week later I went and had it tuned. Gained 4rwhp with tune.

Of course, my car was previously tuned.

 

[firstcapgoat]

Here is one more option. If for some crazy reason you were not planning on getting a tune at all and you did not want any codes, you could get O2 simulators. They make the computer think that there are cats there, when in reality they are not. Personally, I would not go this route.

 

[s/c'd cav]

the simulators dont always work , depends on how picky the car is , also some places are droping simulators

another way to go is to use somthing that spaces the rear o2 sensor out of the exhaust stream , which slows its response to the ehaust , just like it the cat was in and doing its job , pic below of 1

 

[Steel Chicken]

cat codes should be tuned out.
tune is always good, even for a stock car.
it wont hurt if you throw a cat code, but it might run with less giddyup and go.

 

[Blast2Hell]

yeah I'm personally going with the tune right away concept. Kooks LT and catless midpipes go on saturday, got an appointment for a tune on Monday. Only have 1300 miles on the car so far, so I'm hoping I can tell a diffrence after these mods.

 

[Steel Chicken]

You will notice, and you will like

 

[jdo6696]

I have had my Kooks LT's/off-roads on for about 2k miles and it runs fine, rich as shit, but its not slow by any means. I would have done a tune sooner, but other things have taken priority, now I am just waiting for the license from HP Tuners to get started. Basically its not going to hurt anything, but if you want to wait go for it.

 

[04JRB]

While I dont drive my car every day, it drives fine after I installed the headers just burns really rich. Im sure its fine untill I can get it tuned but I am a little worried about ruining the O2 sensors and the Cats from running really rich. I would get it tuned but you should be fine until you do. It will probably pop and crackle a lot like mine does.

 

[BLACK05GTO]

I lost HP with long tubes on my 05 GTO without a tune. They showed me the dyno sheets before and after the header install (without a tune). The headers made my car run very rich. My car was already running pig rich before the headers, and they just made it worse.

But with a tune, I picked up 38 rwhp over my original baseline before headers.

So get the car tuned if your running long tube headers. It will make a huge difference.