Hello all, I have posted before looking for ideas on what might be happening with my truck.

The issue I am having with it is a loss of engine power, around 40 - 50 km/h it doesn't want to go over 1500 to 2000 RPM.

I have run some data logging on various parts, and found something now, but not sure exactly where to go. So I am hoping someone will have some advise.

I checked my O2 sensor readings and both bank 1 and 2 sensor 1's are switching as they should, however bank 1 sensor 2, is stuck high at just under .7 volts. Bank 2 sensor 2 is sitting down nicely near .1 but it does move around a bit.

I checked my fuel trim levels as well. Once warmed up, LTFT bank 1 is around 5.5 short term moves around from 1.5 to 2.5. Bank 2 sits at 1.56 LT and seems to move between -.78 and +.78 (with a couple spikes, nothing more then +/- 2)

The difference in LTFT between banks is worse when the engine is warming up. I see 10 - 15 on bank 1 long term paired with + 3 to 5 short term while bank 2 sits around 7 LT and short terms of between +/- 3

No engine lights are on, there is one code P2006 that shows gray in my scanner (says must be cleared by ECM), I have had the IMRC replaced, but the code is still there in gray.

I am thinking this might be a fuel delivery issue, but I am not 100% sure and just wanted some guidance in the right direction.

I appreciate any help you guys could offer.

 

Sensor 2 is only used as a cat monitor, it doesn't affect the way it runs.

 

Ok I thought that might be the case, but I don't know exactly what that value means. I'm guessing that the cat is shot, but not plugged?

 

If the cat were shot (low efficiency) you should throw a P0420 or P0430 DTC. However, the sensor itself or wiring to it may be bad.

With those symptoms, I'd highly suspect plugged cats. I'd take it to an exhaust shop and get them tested for excessive backpressure.

 

I did have my cats checked already, they said they were fine (I don't know if I believe them now)

IF that imrc was stuck closed on bank 1, would it cause the same symptoms? I am having the problem at rpms below 3000 so I wasn't thinking it would be the issue.

 

Well I got in there this weekend, and removed and cleaned my throttle body, replaced the COP's and used my inspection camera behind the manifold. I found the big wire harness that is supposed to be suspended from the stud on the IMRC motor was laying on the passenger side rod. I tied the harness up out of the way and did the PCM relearn and the code is now gone.

It seems to have power again, but it was intermittent before so I will have to drive it this week to decide.

One thing I did find was a red metal spacer between my throttle body and lower intake. I am wondering if this is stock, or did the previous owner install a spacer?