Headers & Dyno Tune

[Remo]

Recently installed a set of Kooks LT Headers, X-pipe and high flow cats. The car needed to be dyno tuned to take full advantage of the headers. As suspected, the car was a bit lean. Tuning resulted in an additional 12 HP and got the 02 sensors to stop throwing codes. Car now has 469 RWHP and 411 RWTQ.
Remo:cool

[/QUOTE]

 

[6 Shooter]

Remo - I think ya need to get some 1/4 times this summer!

​

Later . . . . . .
6 Shooter

 

[jrose7004]

Remo - I think ya need to get some 1/4 times this summer!

​

Later . . . . . .
6 Shooter

Hey "D"! Have you done your LG Longtubes yet?

 

[6 Shooter]

NOPE - My current 50% work situation has put all non-essential projects on hold!

L8TR - D

 

[geekinavette]

Hey Remo...did you have any issues with the 'puter throwing a "Catalytic Converter Effeciency" code (after the high-flow cats)?

Bill

 

[Remo]

Hey Remo...did you have any issues with the 'puter throwing a "Catalytic Converter Effeciency" code (after the high-flow cats)?

Bill

Bill,
Yes I got 02 codes right after the installation. It was expected and the dyno tune guys took care of the recalibration during the tune up.
Remo:cool

 

[geekinavette]

I'm not sure that we're talking about the same thing. (maybe?)

One of the side effects that the catalytic converter has is to "average" the closed-loop rich/lean back and forth swing that is all too common at the front (pre-cat) 02 sensor. At the rear (post cat) sensor, this "swing" is very very small. The 'puter monitors this difference, and if the "swing" at the rear 02 sensor is not reduced enough (as is often a result of high-flow aftermarket cats) the 'puter will throw a "Catalytic Converter Efficiency" code. It isn't so much a 02 sensor issue (like too rich, too lean...etc), strictly cat. con. related.

Are we talking about the same thing? If so...did they simply reduce that threshold? Or just disable that code alltogether?

Thanks,

Bill

 

[Remo]

Rear 02's Throwing Codes

I'm not sure that we're talking about the same thing. (maybe?)

One of the side effects that the catalytic converter has is to "average" the closed-loop rich/lean back and forth swing that is all too common at the front (pre-cat) 02 sensor. At the rear (post cat) sensor, this "swing" is very very small. The 'puter monitors this difference, and if the "swing" at the rear 02 sensor is not reduced enough (as is often a result of high-flow aftermarket cats) the 'puter will throw a "Catalytic Converter Efficiency" code. It isn't so much a 02 sensor issue (like too rich, too lean...etc), strictly cat. con. related.

Are we talking about the same thing? If so...did they simply reduce that threshold? Or just disable that code alltogether?

Thanks,

Bill

Bill - they did both things. First, they richened the fuel mix as it was running a little lean which, as you know, is characteristic with a higher flowing engine. But to be clear about this, the pre-cat 02's never threw codes after the new headers were installed. Secondly, they reprogammed the PCM to be satisfied with the lower heat range readings coming from the rear 02's, which were the ones throwing the codes.
Remo:cool

 

[Bob Chadwick]

Glad you got it working Remo. A lot of posts out there from guys sweating bullets because this enhancement has them throwing codes, have no idea about how to fix it and the emission test is coming up quickly.

 

[geekinavette]

Yeah I think we're talking about the same thing. I have a similar issue with a different car and aftermarket cat...I think maybe just the code description might be worded a little differently.

Thanks Remo...sure looks purdy!

Bill