Hey all, had a few questions. My 08 Envoy 5.3 had an afm lifter lock up, so I installed an LSXceleration kit with a 212/218 stage 2 cam, non afm valley cover, new lifters, 3 bolt cam gear, and a K&N filter. It starts and runs nice, but it doesn’t want to go when you step on the gas. Replaced the pedal sensor and throttle position sensor, no change. If I get it up to speed it goes, but I can get it stuck on the slightest incline, put the pedal to the floor and it just won’t go. Now I haven’t had it reprogrammed since putting the kit in, and I tried disconnecting the brake booster sensor, no change. Am I having a problem simply because it hasn’t been reprogrammed yet?
2008 Envoy Denali issues after DOD delete
- Thread starter John338
- Start date
Welcome to GMT Nation...
With the installation of your New Performance Roller Camshaft Profile not being a trivial change, you will require a 'Professional Tune' be made to the PCM in order for it to deliver the correct AFR in ALL RPM and Power ranges of operation. These changes must always be done... Hand In Glove.
It would also be wise and worthwhile to get the fairly pricey Wide Band AEM Bosch Oxygen Sensor and an AEM AFR Dash Gauge installed in order to keep out of trouble if you intend to freelance further with adding other Performance Upgrades.
These would include Adding Headers, Deleting the CAT-Can and/or adding a CAT-Back System, as well as changing to a Fatter CFPM Throttle Body. All of these 'untuned' changes can decide whether or not your Truck will run properly, but also be able to pass any Annual Smog Inspections.
In the mean time... Beware trying to raise your engine RPM above an idle too much, as the Non-Stock Air to Fuel imbalance in evidence right now can lean out enough to damage your Valves. Best to have your truck quietly towed to a decent Tuning Shop after locating one with a Good Reputation and work things out well in advance or be prepared for some incidental "Wallet Surgery" that will lighten its weight considerably... Post-Op.
You don't mention having a Tech 2, a GM MDI and HP Tuners Equipment & Software facilities along with the skill set for using all of them in combination, but you should also consider having your PCM-ECM Calibration Updated BEFORE you have the New Tune .BIN File installed by the Pros to get all of the outstanding updates included.
Remember ... if you visit a Dealership for later Service and Repairs... they can accidentally Wipe Out your Custom Tune in a Heart Beat, so be careful about leaving the Truck in the hands of anyone 'uninformed'.
With the installation of your New Performance Roller Camshaft Profile not being a trivial change, you will require a 'Professional Tune' be made to the PCM in order for it to deliver the correct AFR in ALL RPM and Power ranges of operation. These changes must always be done... Hand In Glove.
It would also be wise and worthwhile to get the fairly pricey Wide Band AEM Bosch Oxygen Sensor and an AEM AFR Dash Gauge installed in order to keep out of trouble if you intend to freelance further with adding other Performance Upgrades.
These would include Adding Headers, Deleting the CAT-Can and/or adding a CAT-Back System, as well as changing to a Fatter CFPM Throttle Body. All of these 'untuned' changes can decide whether or not your Truck will run properly, but also be able to pass any Annual Smog Inspections.
In the mean time... Beware trying to raise your engine RPM above an idle too much, as the Non-Stock Air to Fuel imbalance in evidence right now can lean out enough to damage your Valves. Best to have your truck quietly towed to a decent Tuning Shop after locating one with a Good Reputation and work things out well in advance or be prepared for some incidental "Wallet Surgery" that will lighten its weight considerably... Post-Op.
You don't mention having a Tech 2, a GM MDI and HP Tuners Equipment & Software facilities along with the skill set for using all of them in combination, but you should also consider having your PCM-ECM Calibration Updated BEFORE you have the New Tune .BIN File installed by the Pros to get all of the outstanding updates included.
Remember ... if you visit a Dealership for later Service and Repairs... they can accidentally Wipe Out your Custom Tune in a Heart Beat, so be careful about leaving the Truck in the hands of anyone 'uninformed'.
You know I thought it might just be really lean; I sprayed some cleaner in the throttle body and the rpms picked up considerably immediately. Normally it makes a vehicle want to die but it ran better than ever. Ok, so it sounds like I just need the tune done and possibly a wide band. I don’t know any local shops that do tuning but I did talk to someone at PCM of NC and they said they could do a tune through mail so I’ll probably go that way. Thanks for helping me piece together my next step, greatly appreciated!
