Exhaust system help D17A1

[gmcuajo]

I installed a custom design exhaust system that run a JDM Style 4-1 Header, no cat (free flow resonator) and 2 inch cat back.

I think the engine is loosing its exhaust back pressure at low RPM, beacuse it becomes to accelarate faster from 4,500rpm. Do you know anything I can do to it?

[Tobias]

I can only assume that you were expecting noticible power gain. You won't feel much @ all or @ least I didn't. I ran a similar setup w/ my 03 lx. Also higher rpm's = faster acceleration and @ 4500 up, your car or any car for that matter, will gain speed much faster. Unless there is a specific problem your car does @ low rpm's such as a sputter or hesitation. By the way, how's your check engine light?

[jimmyb34]

4-1 headers are more for top end, hence power coming on above 4500
if you want lod end/midrange get a 4-2-1

[MyblkVTEC]

4-1 headers are more for top end, hence power coming on above 4500
if you want lod end/midrange get a 4-2-1
yet again, he said what I was gonna say, 2inch is fine, you shouldnt be losing anything from that, hell I reccommend 2/1/4 on NA and 2.5 inches on boost applications.... but even when I boost im gonna stay with my 2/1/4 catback.... works well.........

[gmcuajo]

By the way, how's your check engine light?

The MIL (malfunction indicator light) come on instantly, but I already install a MIL eliminator on the secondary oxigen sensor.

[Tobias]

The MIL (malfunction indicator light) come on instantly, but I already install a MIL eliminator on the secondary oxigen sensor.
I ended up doing the same thing. Your ecu should be getting a normal signal so there's no worry about air/fuel mix.

[big_daddy_b_99]

be careful with some of those mil eliminators. i had one mess up on my old 02 lx and it messed up the o2 sensor and made the car run HORRIBLE! Casper electronics makes the best o2 mil eliminators and o2 sensor extensions. they are plug n play but pricey.

[gmcuajo]

be careful with some of those mil eliminators. i had one mess up on my old 02 lx and it messed up the o2 sensor and made the car run HORRIBLE! Casper electronics makes the best o2 mil eliminators and o2 sensor extensions. they are plug n play but pricey.

The MIL eliminator is just on the secondary O2 sensor. The secondary is for cat eficiency. Even without the secondary the car must not change at all.

[jimmyb34]

your car will run no different if the cel is on or off, all it does is let you know if you have a functioning cat or not