Need help diagnosing a loss of power problem

TeflonTrout

New Member
Joined
Apr 18, 2019
Messages
7
Location
Pennsylvania
So I recently had a major loss of power in my 04 TJ 4.0L Manual transmission. Pulling out is difficult and accelerating is super slow.

I recently cleaned my throttle body, changed spark plugs, changed my MAP sensor (had a Mass Air Flow OBDII code) and I also fixed an exhaust leak a few months ago.

There is no CEL at the moment but I can definitely tell there is a loss of power. Any advice?
 
Had that loss of power thing in my 05 2.4, replaced 02 sensor upstream and down. No more loss of power.
Wouldn't that throw a code, I guess they could just bee cheap O2 sensors from the previous owner. I checked my backpressure and I want to think the muffler/back cat is slightly clogged. I'm going to have to do some exhaust cutting after my emissions :rolleyes:
 
Wouldn't that throw a code,
Not necessarily.
how many miles on vehicle? Too many probabilities to list. Start with the obvious, take it down the highway pull off the road and coast to stop, try not to use the brakes too much. Feel each wheel to make sure they are not hot, eliminate brakes hanging up. You already changed plugs. Clogged air filter, fuel filter, weak fuel pump, injectors, the list goes on. I would check all these first before pulling exhaust,,, easier to check and replace.
 
Not necessarily.
how many miles on vehicle? Too many probabilities to list. Start with the obvious, take it down the highway pull off the road and coast to stop, try not to use the brakes too much. Feel each wheel to make sure they are not hot, eliminate brakes hanging up. You already changed plugs. Clogged air filter, fuel filter, weak fuel pump, injectors, the list goes on. I would check all these first before pulling exhaust,,, easier to check and replace.
Thanks for the rapid response, I checked fuel pressure it was reading about 42-46 psi. I changed the air filter a while ago and I even changed my MAP sensor. I really want to think it is clogged exhaust/cat