[skeldon13]

i just purchased a stromung cat back exhaust and i want borla headers. some people have told me not to get headers because its easy to mess up the o2 sensor changing headers. I would juts like to know if anyone came across this problem going from stock to borla and if you did how did u change it. thanks

Evan

 

[Supers587]

There's no o2 sensor in the header. You might get a P0420 code (catalyst inefficiency), which can be fixed with an MIL eliminator, o2 spacer, premium gas, header wrap, or a combination.

/thread

 

[skeldon13]

thanks.. would a new high flow cat fix it as well??

 

[rallifreak]

thanks.. would a new high flow cat fix it as well??

that's actually a sure-fire way to get a P0420 CEL (I know, I have one)

 

[skeldon13]

that's actually a sure-fire way to get a P0420 CEL (I know, I have one)

does that cause any problems to your engine??

 

[Supers587]

does that cause any problems to your engine??

No, but you won't pass emissions, and your gas mileage will suck.

 

[skeldon13]

No, but you won't pass emissions, and your gas mileage will suck.

thanks. so where it said at boxer4racing with the stromung highflow cat and the borla headers a 9% fuel economy increase isn't true?? thanks

Evan

 

[Supers587]

:lol: I doubt it.

 

[Dojoep]

the fact that the exhaust can free flow instead of causing backpressure can increase mpg *a little bit*....but if your like me you wanna hear the rumble and step on it more...which means horrible mpg

 

[Supers587]

Taking the average 25mpg and multiplying by 9% gives you about 2.25, which would be 27.25 mpg average. I don't think it makes that much of a difference, IMO.. but I guess it's possible.

 

[JoeMack]

im running UEL headers, 04 WRX cat back, WRX-RA Trans (higher rpms on fwy) and I'm now getting the best mileage ever. The RA Trans I guess puts the car at a higher RPM that has more torque so i give it less gas?

I dono, but I am now "NOT READY" anymore cause of the P0420, but am getting great mileage.

 

[cyhm]

The HFC will make your MPG suck. And you don't really want to not pass inspection do you??? Just the stromung CBE alone would raise it a little, but not enough to make a difference. And the only way you get it is if you baby it and you do like 15mph under the speed limit lol As for the Borlas, I'm not too sure, because i'm in the process of getting my borla replicas, but everyones sold out and none are up on ebay at the moment.

 

[HondaH8er]

No, but you won't pass emissions, and your gas mileage will suck.

Not necessarily true about the gas mileage. I have an AVO turbo kit with it's high-flow cat on my car, and I get the P0420 quite often (about every 100 miles), yet I'm still getting 26-28 MPG on a tank of gas. Stock manifold, AVO up and down pipes with single high-flow cat, stock midpipe, and Stromung axle-back muffler. Really need to upgrade that midpipe, it's like a cork right in the middle of my exhaust.

 

[MyBluFlameRS]

/\ +1 about the mileage.
I have wrapped Borla reps, R/T HFC, Custom mid, and a Prodrive axleback. I, too get a CEL every 150 miles. But I have no issues with crap for gas mileage.

 

[skeldon13]

thanks for all the info.. so i should be fine with all the check engine lights and stuff is i just get the borla headers with my stromung catback?

 

[skeldon13]

and im not too concerned with the gas millage too much.. i just dont want the check engine light to come on lol

 

[Reebis]

I don't know where all this stuff about horrible gas mileage is coming from. I have Borla replica's, RT HFC and a Borla CB and I get 28-30 mpg's on the highway.

 

[HondaH8er]

Do what I did to deal with the CEL: get a ScanGaugeII. Now, when my CEL comes on, I can scan it, see what code it is, and clear it in less than 10 seconds without even slowing down.

 

[rage557]

I have a randomtech HFC, I am throwing 4 codes and I have not noticed a difference in MPG

 

[RSJeff]

so whenever a cel light comes on the car will automatically run richer and what not and cause bad mileage or is it only for certain cels? I have a scan gauge with my borla setup and I might as well leave it on if it isn't going to affect anything.