Hey guys I have an interesting one here. I added an exhaust cutout before my muffler. I have a Cherry Bomb extreme single chamber with both resonators removed. After the install everything worked fine. Test drove and then parked it. Then the next time I started it up the truck went into Limp mode right away. Check engine on and basically stuck in third gear. Put the plate back on (manual cutout from summit) and started it up and it was fine. Tried resetting the computer and did an idle learn and same thing happened. Ran fine first time out then limp mode after that at startup.

What do you think the culprit could be? I have read about o2 sensors causing problems and possibly limp mode. And that maybe the first test run was not long enough and it would have gone into limp mode after warming up.

Should I try swapping all four o2 sensors or just the downstream ones?

I appreciate any feedback. I really want to open it up and even possibly gut the cats but not until I can at least uncork the cutout.

Thanks.

 

The code will tell you what's wrong. Get it read and post it here and we can help.

 

Definitely get the code number. It doesn't help to start swapping sensors until you know what the code is telling you. You can go to AutoZone or Pep boys and they will read it for you, or you can buy a scan tool fairly reasonably. With all the sensors and electronics, and the fact it is throwing a code, there is not much help swapping parts is going to do.

 

So my truck is a bit weird. Everybody has problems reading it unless the truck is started. I had the Tranny rebuilt about 6 months ago. It is showing p0700, u0101, p1603 in the history But I think those are from the rebuild or before.

It has to be something related to the exhaust because i can literally shut the truck off while in limp mode, put the plate on the cutoff, start the truck and it will be fine. I guess I am just wondering if a downstream o2 sensor could mess it up and it be fine with the normal backpressure and not with the cutout.

 

I just ordered a bluetooth obd2 scanner same day shipping and will see if I can get anything from that. Worse case I will be able to see live stats and see what the changes are when the cap is off. We shall see.

 

There will be a code stored. That will point you in the right direction.

 

Awesome yeah it is on the way I will update once I read the codes. Kinda excited to use this scanner and the torque app. Thanks again.

 

So the check engine light is on and all it is throwing is tcm, pcm codes.

p0888
p0700
p1603
and a pending u0101

I am guessing these codes came up because it went into limp mode?

I can't believe this truck is so sensitive that a change in the exhaust would throw so much off.

 

Check here for causes and solutions.

https://www.obd-codes.com/

 

p0888:
p1603: