Installed Offroad H and flowmaster catback now car feals weaker?

[96cobraboy]

on my 96 cobra the owner before me basically had a open exhaust fom the cats back. he had the cats on the stock cat converter, but these turn down pipes went out from the cats and formed a X then went under the axles. It sounded decent but I wanted tailpipes back for the look.

So I went with a Offroad H and a flowmaster catback..

The car feels I guess less grunty but im not sure if its any slower. Just the Butt dyno.

does the offroad H change the powerband and allow me to feel what im feeling? I just hope theres not something wrong?

Anthony

 

[Stus99GT]

The H-pipe should feel stronger on the low end. Usually they give more low-end torque.

I notice that you went with catless. Did you get MIL eliminators or a tune? If you didn't that would be why the car feels sluggish. The CPU picks up a code and goes into limp mode.

 

[96cobraboy]

yeah its still got the codes... Its got a code for running lean, Cat efficiency codes, Low idle- sometimes stalls..

What does everyone think does this effect the ecu's tuning and do limp mode?

what exactly does "limp mode" change?

 

[Stus99GT]

yeah its still got the codes... Its got a code for running lean, Cat efficiency codes, Low idle- sometimes stalls..

What does everyone think does this effect the ecu's tuning and do limp mode?

what exactly does "limp mode" change?

Basically it puts the CPU into "Safe Mode". This limits the engine (in many different ways) and hurts power. You need to get MIL's (Dallas Mustang) or, if you want to spend some money, you can get a hand held tuner. Otherwise your car is going to feel weak

 

[DTNODYA]

I think it retards your timing or somethin'

 

[Twista]

I think it retards your timing or somethin'

what you call me?

 

[thomas91169]

lol yeah, you lost some backpressure. throttle response probably feels a little more sluggish. with a open exhaust, you will lose a few ft/lbs down low, but youll make up for it up top, where the cats would usually choke up the exhaust. your powerband has shifted a bit higher.

if the o2 codes really affect the tune (which i dont think they should, the rear o2's are just for obdII diagnostics to make sure the cats are working effectively, since you have no cats they are pulling a code to tell you your cats are failing, but you already know that), then id get a handheld tuner to just modify the parameters to get rid of the o2's completely. and to help with that low end get-up, a set of gears might do the trick, i dont think you can compensate for gears in a 96 though, i think you need the actual speedo gear to account for them.

 

[madmatt]

It should feel slower down low, because you lost a LOT of back pressure, however, top end should feel the gain. H pipes dont make more torque, however, theyve been known to make more torque than an off road X.

And the CEL shouldnt put your car in limp mode.

 

[Stus99GT]

It should feel slower down low, because you lost a LOT of back pressure, however, top end should feel the gain. H pipes dont make more torque, however, theyve been known to make more torque than an off road X.

And the CEL shouldnt put your car in limp mode.

How do you figure that the CEL doesn't put the car into safe mode?

 

[madmatt]

Ive just always read that even with a Mil related CEL, no one ever notices their car running slower from being in safe mode. Some people drive with the CEL on all the time.