Hey everyone, just to let people know i'm new to this site. Anyways, I'm considering getting an XLR8 j pipe and either a High flow cat or a test pipe and i was just curious about a couple of things.

First of all i am curious to know what the power change would be like with a High flow cat and j pipe and a test pipe and j pipe? Also, would the car sound a lot different? I bought my TL with a comptech exhaust system on it and i'm relatively sure that it still has the stock cat.

So if anyone knows the answers to these questions or has any suggestions as to what i should do they would be much appreciated.

 

Oh, I forgot to say that my TL is a 2004 6MT. And the comptech exhaust is only catback, so it definitely still has the stock cat.

 

The j-pipe and high flow cat combo or the j-pipe and test pipe combo will net you about 15-20 hp/tq. Our high flow cat is a 200 cell metallic core. The difference between the test pipe and a HFC is literally 1 hp. The HFC flows extremely well and is not restrictive like the stock cat.

The sound will be altered slightly since you are flowing more exhaust; it will be a bit deeper and throatier. If you delete the cat it can get more aggressive whereas the HFC setup is a little less aggressive.

 

Oh alright cool. I have been rethinking if I want to get the j pipe though, so how much horsepower would i get with just the HFC on the car?

 

Not much, the stock jpipe itself is a big restrictor. I just installed XLR8's jpipe and it was a noticeable improvement not only in power and torque but in driveability. There is a much more linear power curve now as opposed to the faux-turbo feel when VTEC kicks in.

FWIW I'm still running the stock TL-S 3rd cat. You live in CA it seems, I'm surprised you're even thinking about removing cats at all living in that Nazi state. State PD might pull you over, impound your car, capture and sell your first born son, etc.

 

The j-pipe is the major factor in that power increase; the test pipe or HFC only adds a few hp.

 

Its not that bad like everyone thinks. i live in socal myself and i have had a f-150 with long headers and straight pipe with only one super forty flow,aster exhaust and never got pulled over... for that...lol. and it has really lifted so the cops could have easily taken a look under and seen my set-up. i even got pulled over for roasting my tires and even then they didnt say anything about my exhaust he just mentioned reckless driving, tinted windows, and loud sound system

i also had a 96 mustang 5mt, with complete straight pipe and never had any issued due to the exhaust, i sold it to a co-worker like 3 years ago and he hasn't had issues yet.

so OP, its not as bad as it sounds with the cops, on the other hand if you get caught street racing then i hear they do a full inspection and you must put all oem parts back on or they will not relase your ride. which is why i have ALL my oe stuff in my garage...lol. just in case.

 

Thanks for all the info everyone, I'm thinking I'm going to go with the HFC and the j-pipe. The HFC shouldn't be illegal in California since it's still a cat right? Also would these things be pretty easy to intall myself?

 

Any modification of emissions components in CA is technically illegal.

Yes they are fairly easy to install.

 

Alright well I'm definitely set on getting the HFC and J-pipe now. Just out of curiosity, and this might sound like a stupid question, but where is the J-pipe located on the TL? Is it pretty much right after the headers and before the cat?

 

Also would an AEM cold air intake for this car do much in terms of power?

 

The j-pipe is after the pre-cats. It can be seen in the following diagram.



Yes it will make roughly 10 hp or so.

 

Might want to do a search next time. Guys you were def right that my J-pipe thread wouldn't stop these repeated threads...lol. Can't say i didn't try. .