Stalling when taking off

I'm thinking something simple, like a dirty MAF sensor or a bad MAP sensor if your engine has that instead and could be a borderline Oxy. sensor if it hasn't been replaced in a while, Do you remember what the code was? If you can, maybe some of the others can give you a better idea. I think someone here on this group had a link to a web page that detailed the cleaning of a MAF sensor, so you may be able to Google and find it. If it's running Rich these sensors may be giving the ECU the wrong signal! And it could be the Throttle position sensor as well...I'v seen these with a bad spot on them and they make the ECU go nuts and may not show up on a scan. You have to check it with a Analog type multimeter on the connector and watch for a smooth swing of the meter needle Anyway just my two cents.

HTH, Rick

I installed a new precat O2 sensor in March, problems started before that & didn't get any worse after that. The codes I wrote down were P0113 - Intake Air Temperature Sensor Circuit High Voltage (no longer shows up), P0172 - Fuel Trim System Rich (still shows up) and P0440 - EVAP System (no longer shows up). The last (P0440) is just a general about the EVAP canister.

I did look around the groups some more (should have done that first, getting upset with this problem) and found something about disconnecting a 4-wire connector from the TCC. I did this and the car seemed to run better for a bit until i had to sit and idle for a couple of minutes at a gate, then it stumbled before accelerating. The only other thing I noticed after disconnect the connector was that I no longer had any indication of PRND321.

Now I would think that the O2 sensor for bank 1 needs to be tested. A P0172 is system too rich bank 1.

Rick

What you describe does not fit the symptoms of a failing TCC solenoid. Everything you describe fits a vacuum leak or stuck EGR, however. AND the TPS may be bad, also

I forgot to ask on my last post but why did your disconnect the Torque Converter Clutch connector?? AND the other codes that are not coming up but showed up before, bother me, and I say this because they may still be effecting the base symtom of the rich bank 1....The EVAP SYS. code too. If your in the habit of TOPPING off your tank ,instead stopping on the first click, this habit is a known killer the EVAP CAN. by flooding the CAN with fuel

True, but based on what I've been reading, I was attempting to disable the lockup torque converter solenoid, which seemed to be a common problem with my year & model of transmission (4T60E I believe), use up the cheap solutions first. I have thought about EGR (mine is the $200+ solenoid type), however, I've gotten no codes related to the EGR (P0401, P0403, P0404, P0405, P1404). I've inspected for vacuum line leaks and lines that have been damaged or removed and not replaced, none found so far, though it still may be a vacuum leak someplace on the engine.

I do top off (I like even $0.50 increments) and now that I know about this, I'll stop to see if this helps. I'll also pull the EVAP canister off to see it's general condition, i.e. cracks, broken lines, etc. Thank you. I've also decided to replace the fuel filter since it has been over 75,000 miles since I last did this and because we've got "dirty" fuel out here in Arizona (dust storms and the such), my last filter was plugged solid with dirt and debris.

Thanks for the info. It still sounds like egr is remaining open and letting air into the system. That would also account for the rich mixture - ecu trying to adapt. Can you take the EGR off, take it completely apart, and clean it? Almost forgot - you probably already did these: clean all around the throttle plate - take it off would be best. (Sometimes the throttle body gasket leaks and creates your type of problems clean the maf/mat sensor - its fragile - be careful - inspect the outside for cracks.

I think your throttle body is gunked up. When the throttle plate closes it is closing on a line of gunk which is killing the airflow. Take this apart and clean it out.

Ted