Redneck Truck

Revs take a long time to drop after releasing throttle, as if it takes a second for the throttle body to close. With the A/C off ONLY, revs stay at 1800rpm in neutral when coming to a stop, and stay that way until I turn the A/C on or steer side to side.

No trouble codes (partially due to an ECU tune), but EVAP and SAI monitors not ready, do not have SAI system, don't know if EVAP system works because I can't get it to initiate the tests in basic settings 70 and 71.

So far, have replaced:
B1S1 o2 sensor (internal resistance too high code)
suction jet pump
crankcase vent valve
EVAP purge valve

Compared coolant temps in measuring blocks between ECU 001 and Instruments 003, and show the same temperature consistently, coolant temp sensor is the updated green one and tests good. No vacuum leaks that I've been able to find, all check valves I'm aware of work fine, and there is fuel vapor at the EVAP purge valve. Does anyone have any suggestions of stuff I might be missing?

2.7Lturbo

dude thats weird as hell, i double checked and yeah my car dont do that what are the timing logs when it happens?

Just Me

vacuum leaks can cause odd behavior

Tranny ECU has some control over throttle and decel

EPC can hold the throttle for a moment

The big question is why no codes. You say you did something to the ECU. Does it suppress codes? If so, bad idea IMO!

Redneck Truck

The only potential vacuum leak left is the intake manifold, and I'm replacing that as soon as I find some gaskets. I could also replace the MAF and the other o2 sensor, but I don't want to if they aren't bad. TCU is gone and the ECU doesn't throw a code looking for it, but the ABS does. EPC.. good information. Is that part of the ABS system? I wonder if there's a way to test if that is what's causing this.

Redneck Truck

As for suppressing codes, I still get trouble codes. When I removed the SAI vacuum control valve, I got a CEL and a code for that. My tuner buddy said "crap! sorry man, we'll get rid of it on the next flash." However, he supposedly coded out the secondary o2 sensors, and he definitely coded out the TCU.

5v/cyl

You could also check the throttle body for leaks and dirt/buildup. Clean and inspect then do a re-adaption.

Redneck Truck

Today, I will be replacing the throttle body, intake manifold, fan clutch, belt tensioner, idler, valley pan filler plate, o-rings, coolant pipe o-rings, and hopefully rigging up an e-fan to replace my dead one. Anything else you guys recommend doing while I'm in there?