Cannot figure out how to avoid REP mode when hitting 5600RPM

[hirdlej]

Ok gang, I just swapped a 6.0L into a '04 2wd Silverado with a 5 speed manual. Mods on the engine are 10.6:1 comp, ported 243 heads, comp 218/224 cam, long tube headers with no cats. Attached to this post is a copy of my latest tune. I was doing some STFT tuning adjustments tonight (I'm going to be running SD) and discovered in a hell of a hurry that my truck continues to go into Reduced Engine Power when I hit 5600 RPM's. When this happens I push the clutch in and the tach will drop and stay steady at 3,000 RPM's even and no inputs from the gas pedal makes any difference. I have to clear the code, shut the truck off. Wait and restart then all is fine again. The truckload of codes that are being thrown is in the screen shot below. By looking at this, can someone tell me if it looks like I may not have all my grounds hooked up properly (late and don't feel like crawling around in the dark tonight) or is this problem I'm having found in the tune somewhere? Please have a look at my tune and see where my problem is and why I'm hitting REP. If I can get past this bug I can handle the rest of the tuning myself

[RedHeartbeat]

Considering that the 02 sensors test did not complete I would guess you left the ground for the sensors disconnected from the back of the block.

[hirdlej]

PROBLEM SOLVED = It may have been one or a combination of things. Here's what I did that solved the issue.

• Increased cyl volume size to 0.74590
• Under ENGINE DIAG raised the calculated airflow vs. tps vs. RPM to 4.10 (as high as it would go)
• Increased maximum Delta Airflow to 2.5 times it original size
• Also increased error map calculated max to 320 in every cell.

Don't know if I can leave these alone as high as they're set but I'm not seeing anything funny while tuning the STFT's and I had 'er up to 6100 RPM without sweat with no REP errors. I still have the same DTC's set in my PCM so I don't know what the hell that's all about. I do want to make one more comment though, I don't know how you guys drive **** like this everyday. This thing is nasty and almost too much for a daily driver. You can't take off hardly without snapping your neck or burning rubber. I went to pass a car with moderate throttle, not WOT in 3rd gear around a gentle curve and you could tell the ass end wanted to break loose and slide. Now I know why a RCSB truck never got a 6.0L in it. It's pretty unsafe. I'll check the grounds tonight again tonight. Even if they look good I'll remove them, clean and reinstall snugly

[hirdlej]

Also riddle me this, if the ground for the 02 sensors wasn't hooked up, how could the PCM get a reading for me to calibrate my STFT's?

[RedHeartbeat]

It must be something else not allowing the 02 sensor tests to run. They probably run in stages as other tests complete. The first test fails, they all fail?

[hirdlej]

Well, if the maf fail is set to 0 would this cause the 02's to not finish their readyness tests?

[jtaliaferro]

Well, if the maf fail is set to 0 would this cause the 02's to not finish their readyness tests?

No.. I am pretty sure my 02's completes the readyness test with the MAF set to 0. I will make sure unless someone more knowledgeable beats me to it.