Need help...just installed header.

[venturaII]

Originally Posted by Detroiter

In order to not start a new thread and on a somewhat related note I installed my catless headers over a month ago with what I always assumed was the stock tune. I have yet to get a CEL from the O2 sensor. I've tried searching and couldn't find much info on it. Anyone have any ideas why this could be?

Have you owned the car since new?

[Detroiter]

Originally Posted by venturaII

Have you owned the car since new?

Sure haven't, My first thought was the previous owner could have tuned it as well but I have not seen a more bone stock looking car than this one when I got it. All the exhaust parts had definitely not been taken off since the factory. Never got a CEL when running it hard stock and wouldn't the O2 only be coded out if it has a stage 2 tune on it?

[venturaII]

Originally Posted by Detroiter

Sure haven't, My first thought was the previous owner could have tuned it as well but I have not seen a more bone stock looking car than this one when I got it. All the exhaust parts had definitely not been taken off since the factory. Never got a CEL when running it hard stock and wouldn't the O2 only be coded out if it has a stage 2 tune on it?

That's my understanding as well, but I have no experience with it. I'm sure someone with firsthand experience of headers and tunes would be able to explain.

[mav1178]

Originally Posted by timmydatooth

I'm just kind of surprised because my car doesn't sound like the ones in the youtube videos of other people installing tomei UEL.

Because 99% of YouTube uploaders use the default mic on their recording device (GoPro, cell phone, whatever) and they generally do a poor job of recording the actual sounds.

Very rare do you have someone using an external mic for a simple exhaust or header sound clip.

[churchx]

And then it's get played back on laptop's speakers. Right way to evaluate & compare tone & loudness of aftermarket exhaust.
Well, at least real thing will sound better?

[timmydatooth]

So after driving it around a bit I came to the conclusion that adding the tomei uel pretty much made my q300 sound like an n1 now. It's quiet when I'm just cruising but when I get on it it has that rumble with a little bit of rasp to it. As for the performance difference from the stage 1 to the stage 2 tune. I'm not really impressed. Maybe because my expectations were too high and also because going from the stock tune to the stage 1 was way more of a noticeable difference. Overall I'm happy with it but damn...I'm sure cops will be attracted to my car now lol.

[enouf]

I've had PSR UEL header (similar to Tomei) installed a few months back and can confirm the exhaust leak-like, wispy sound whenever you're on the gas. I thought it was a leak when I left the shop so I had them double check it and it was fine.

Like others have said, it's most likely due to lack of shielding around it to dampen the sound of the exhaust flow. It hasn't gone away so I've learnt to live with it. You certainly can't hear it from outside the car though, so that's a good thing.

Just pretend it's a turbo spooling up every time u hear the sound

[Poodles]

Headers "sing," completely normal. You should hear the difference going from cast iron monstrosity of an exhaust manifold to a high end header...

[timmydatooth]

My current exhaust set up is as follows - tomei UEL, tomei OP, invidia catless FP, invidia Q300. Is it normal that this set up has some rasp to it? I understand running fully catless will cause loudness but not so much rasp. Its not constantly raspy, only when im taking off from a complete stop at around 2k - 4k rpm than it smooths out and becomes a deep growl.

[Brayden_23]

Originally Posted by Detroiter

In order to not start a new thread and on a somewhat related note I installed my catless headers over a month ago with what I always assumed was the stock tune. I have yet to get a CEL from the O2 sensor. I've tried searching and couldn't find much info on it. Anyone have any ideas why this could be?

From my understanding, this is dependent on each individual ECU as well as open-loop vs closed-loop driving. For some people it takes months for the CEL to pop up and for others it's almost instantaneous. Again, this is just my understanding based on what I've read and I am by no means an expert.

Maybe @steve99 can provide more insight?

Are you the original owner? Very possible if you aren't that the original owner had it tuned and just didn't reveal that tidbit of info..

[ajcarson11]

Couple things:

1. As many others have said, the 'windy' 'sand rushing through a metal can' 'raspy' sound you hear is from the thin walls of the header. You will hear this a lot on acceleration with the stock catback (since it is so quiet). With the q300 it'll be present, although should be a little less noticeable.

2. You won't really hear or feel a rumble until the exhaust and engine is fully warmed up. It takes my car as much as 5-10 minutes (of driving) to get to a point where the rumble shows up. Up until this point, everything sounds thin. A lot of youtube videos feature the rumble that is present on a fully warm car.

EDIT: 3. The Q300 is VERY raspy with a catless front fipe. Even with a catted front pipe you will notice some rasp. I'd recommend keeping the stock front pipe. This will eliminate most of the rasp. Source: I watched a buddy go through all the variations of front pipes with the Q300.

[Detroiter]

Originally Posted by Brayden_23

From my understanding, this is dependent on each individual ECU as well as open-loop vs closed-loop driving. For some people it takes months for the CEL to pop up and for others it's almost instantaneous. Again, this is just my understanding based on what I've read and I am by no means an expert.

Maybe @steve99 can provide more insight?

Are you the original owner? Very possible if you aren't that the original owner had it tuned and just didn't reveal that tidbit of info..

I'm not the original owner and unfortunately I bought the car form a dealer so I couldn't ask them about the car. But I'd have a hard time believing it was tuned as the car was as stock as they come when I bought it. Nothing had been touched or taken off before as far as I could tell.

Anyway to check if there's a tune on it before I buy a OFT? I'm just hoping it's not locked by some shifty tuner the previous owner decided to use.

[Xxyion]

Originally Posted by Detroiter

I'm not the original owner and unfortunately I bought the car form a dealer so I couldn't ask them about the car. But I'd have a hard time believing it was tuned as the car was as stock as they come when I bought it. Nothing had been touched or taken off before as far as I could tell.

Anyway to check if there's a tune on it before I buy a OFT? I'm just hoping it's not locked by some shifty tuner the previous owner decided to use.

You can take it to a tuner or buy the OFT and plug in and check yourself. Might be cheaper to buy the OFT and do the check yourself since you were gonna get one anyways.

Another not so obvious way of checking is to get to second gear and floor it while watching the RPMS. When the car hits 3500 RPMS the RPMS should start slowing down and not climb quite as fast even with your foot down. That should be the infamous torque dip. If you see that happen then you are on the stock tune.

[steve99]

Originally Posted by Detroiter

I'm not the original owner and unfortunately I bought the car form a dealer so I couldn't ask them about the car. But I'd have a hard time believing it was tuned as the car was as stock as they come when I bought it. Nothing had been touched or taken off before as far as I could tell.

Anyway to check if there's a tune on it before I buy a OFT? I'm just hoping it's not locked by some shifty tuner the previous owner decided to use.

Ecu compares readings from front and rear o2 sensors to determine if cat is working correctly. Some headers space the rear o2 sensor back so its not in full exhaust stream this can sometimes fool ecu like an o2 spacer into thinking cat is srill their. As other guys said it depends on driving as well , highway driving is where the cel trips more often, if its all city driving sometimes cel wont trip.


Without some software tools its very xifficult to determine 100% if car is tuned. You can check cvn number against stock.

Alternativly if you use ecutek kit and do a query ecu it will tell you if ecutek licience in ecu or not. If ecutek wont read ecu it likely benn tuned with brzedit.

With oft if it wont read you dont know if its ecutek or brzedit.