When you install long tubes, do you still retain the cats?

If not, how do you pass emission tests?

Thanks,
al

 

You can use hi flow cats or no cats. Without cats you won't pass emissions, but you will have great sound, more power and serious fun.

 

Had kOOKS long tube headers put on at Cartek in Garwood, NJ. They installed them with high flow cats. Haven't put the car through inspection yet. So the answer is you can still use cats.

 

ECS in NJ put American Racing long tube headers and hi-flo cats along with an x-pipe onto my 98. Nice difference in both the sound and the performance.

 

Another dumb question:

Can you use the stock cats, or is that not recommended?

Thanks!

 

You probably could use the stock cats with some adapters, clamps & maybe some welding skill....but why? Go with a nice hi-flo cat.

 

I would think that you are backing up by using stock cats with the LT headers, you would be causing a flow backup....

 

I did both....hi-flow got me only 6 more rwhp. It was much louder and deeper but performnce was not much. IMO not worth the money. Biggest problem you will have are with the oxygen sensors.
You can buy sims and plug them in or just go into your dic and take the codes out

 

I used the stock cats with LT's. From what I've read the stockers flow pretty well and the high flow cats only get you a couple of HP over the stockers.

 

Most of the good header kits will come with hi-flow cats, or give you the option to go catless. I run hi-flow cats, mainly do the smell of running with out cats all together. I am not sure about emissions in PA, I would think they are about the same as in IL... Don't get O2 sims, not worth the money several people I know tried this route and its just too risky the sims are not reliable someties..if I were you, I would go get a dyno tune after you put the headers on to get the O2's shut off to pass emissions (at least that's how we pass in IL since all they do is plug in to the OBD port, no codes and you pass, no visual inspection).

 

I got Hiflow cats on mine! and it passed California Emissions tests!

Thanks,Matt

 

No cats, no emissions tests (YET)

 

ECS installed ARH LT's and high flow cats. Great performance and sound with my Corsa Pace cars.

Chuck

 

Thanks for asking this question. I have to get mune inspected before the end of the month.

I have LG LT's w'out cats.

I will order some tomorrow. I hop eto have them on this week and go take the test.

I did have a friend here in IL that said I should pass as long as they don't inspect the car - but I'm putting high flow cats on - just in case...

 

I have LG LTs. The tubes are long enough that the end of the collector is in the same area as the stock cats would be, making connection to the stock cats and H-pipe a pain. I went with the LG hi-flow cats and x-pipe (including all 4 O2 sensors) and passed two emissions (sniffer) tests in TN prior to moving to a no-test state.

 

All they did was connect to the OBD2 jack and send me on the way. A couple of comments on how nice my car looks and thats it...

I sure am happy - I wasn't looking forward to getting under the car again to install some hi-flow cats...

 

Is the inspection a Cook County requirement?

 

Hello. I live in Northern VA an they do an OBDII emissions test every two years. From what I understand, the system checks for active MIL lights or a history of MIL. You can clear codes on the C5 but there will be history which only gets cleared after a certain number of drive cycles without the problem showing up.

I recently had LT installed and opted for the Hi-flow cats due to emissions. However, I have heard that even with hi-flow cats and O2s working that some cars will still throw an MIL on the rear O2s anywhere from a few 100 to a few 1,000 miles. Think this has something to do with the reduced back pressure and difference in O2 readings from front to rear. I was told the best course of action is to leave the front O2 operatonal and have the tuner tune out the rear O2s. This way you eliminate any chance of rear O2 MIL and you should pass emissions using OBDII check. In VA, if you fail OBDII check, you have one more chance with the OBDII test and then they run a sniffer test. With the above setup, you should be fine. I have another year before I have to test mine but so far no MIL lights and I have been running LTs for about a month.

IMHO if you are going to the expense of putting LTs on, get the hi-flow cats. Most systems like the ARs have a hi-flow cat configuration in the design setup. Trying to use the stock cats is just too much work in my opinion for the money you may or may not save. Good luck with it.