Help. Running bad after exhaust change

[Passelat]

Today I changed back to the stock exhaust becuase of the car check I am going to next week. They wont approve it unless I run with stock exhaust when they are going to measure CO value on the exhaust smoke.
After I changed to stock exhaust (not headers) it is running terrible.
I have to struggle to get it above 4000rpm.
I have not changed back to stock headers, running Gibson.
I changed back to stock tune.
Other mods is, Mopar CAI, Mopar camshaft and JMB catch can.
The truck works good with my other exhaust, straight 3" from headers (Gibson) to rear.
Somebody who can help me?

 

[Fireracer27]

Completely unhook the battery, then hook it back up and let the trucks computer cycle back through. That might fix it. When I put my Magnaflows on thats what the instructions and my exhaust guy said to do. Somebody smarter than me might have another idea. Did your stock exhaust lay outside while you weren't using it. I had a muffler collapse and it did just about the same thing.

 

[TNVIPER]

If I remember correctly the Mopar cam requires a special tune....changing your tune to stock may be the problem...

 

[BLWNSRT]

If I remember correctly the Mopar cam requires a special tune....changing your tune to stock may be the problem...

:dito: I was just going to say the same thing.

Mopar cam requires Pcm upgrade according to mopar performance, or a sct to tune for the extra flow. Put your tune back in and see how it runs

Quote:

B. Camshaft - Race
Based on the Competition Coupe camshaft. Uses production springs
and rocker arms to offer a 6-8 horsepower increase at top end of rpm
range. Recommended for use with Race Engine Controller
(P4510172AB) and 3-inch Race Exhaust (P4510176).
Features:
· Cam lift: 0.320" Intake and 0.320" Exhaust
· Duration at 0.050": 220.00 Intake/230.5 Exhaust
· Cam Centerline = 117° after top dead center
1 P4510171 Camshaft, Race, 2003–06 Viper SRT10

 

[Passelat]

I have used all 3 tunes I have (Mopar, stock and Torrie) and it wont run good. It seems like the exhaust will not flow enough?

 

[Ironhead]

are you reusing your o2 sensors ,,,i would bet you have a bad o2 ,,,maybe bumped a wire ,,,i had same problem and it did not throw a code it would run rough as hell

 

[Shadyscott999]

Did you make sure you don't have a birds nest, rag, possum, family of elves, in the exhaust? :dontknow:

 

[Passelat]

I did reuse my o2 sensors. I was very careful with the sensors becuase I know they are weak.
I also looked inside the stock exhaust and it looked good to me.

 

[TNVIPER]

I did reuse my o2 sensors. I was very careful with the sensors becuase I know they are weak.
I also looked inside the stock exhaust and it looked good to me.

Your O2s will usually cause a CEL if malfunctioning but not always. I had a problem when I first installed the Roe. Forgot exactly what it was but spent about a week trying to run it down. There were no codes being set.

The tech finally noticed that a wire running to one of the O2 sensors had been sodered. Replaced O2 sensor and problem resolved.

You might take it to your dealer and have them use a StarScan to check O2 performance.

Another maybe is the sensors are reversed....right sensor on left, left sensor on right.....this would cause the PCM to receive incorrect data to adjust A/F.