I am thankful for all the folks in this forum, I have solved a few of my issues already and I am hoping with your help I can solve these last problems.
Symptoms:
It does not seem to matter cold or warm start, when I slightly press the gas pedal sometimes the engine will slightly stall then continue. Also, at idle, occasionally RPMs drop toward zero and the engine quickly recovers. Usually once per day when accelerating the engine bogs down like it wants to die around 20mph even when I continue pressing the pedal further down, then it takes off fine. Always when going up medium inclines I have a significant loss of power around 40 to 50mpg and if I get the pedal 3/4 of the way down it will eventually downshift, but sounds like it is struggling to climb. If I have a slight load, 1,000 lbs, my top speed is probably 40 mph up medium inclines. It "feels" like it is starving for gas, or air. The truck shifts fine on level surfaces and even seems to accelerate at a normal rate. One other caveat, we were sitting in construction the other day on a slight incline and waiting on a 4-way stop and the truck kept wanting to die and recover. It seems to have improved recently on its own.
What has been done:
When I bought the truck, not long ago, it had a P0135. It was stalling badly on every takeoff, but that was the only code I had. I replaced the upstream o2 sensor with a Bosch (now I know that was probably not a good idea). I found cracks on the exhaust manifold and exhaust smell in the cabin so I took it in. They replaced the exhaust manifold and also the thermostat (later found a code for that). Personally, I have cleaned the throttle body, replaced the spark plugs, replaced the fuel filter and air filter. I have also ran Techron through twice.
What codes do I have now:
Currently, I have the following codes: P0053, P0410, and P0455.
The truck is a 2003 4.2 I6 LT extended Trailblazer. I hope I have provided enough information and I look forward to your replies. Thanks again.
Symptoms:
It does not seem to matter cold or warm start, when I slightly press the gas pedal sometimes the engine will slightly stall then continue. Also, at idle, occasionally RPMs drop toward zero and the engine quickly recovers. Usually once per day when accelerating the engine bogs down like it wants to die around 20mph even when I continue pressing the pedal further down, then it takes off fine. Always when going up medium inclines I have a significant loss of power around 40 to 50mpg and if I get the pedal 3/4 of the way down it will eventually downshift, but sounds like it is struggling to climb. If I have a slight load, 1,000 lbs, my top speed is probably 40 mph up medium inclines. It "feels" like it is starving for gas, or air. The truck shifts fine on level surfaces and even seems to accelerate at a normal rate. One other caveat, we were sitting in construction the other day on a slight incline and waiting on a 4-way stop and the truck kept wanting to die and recover. It seems to have improved recently on its own.
What has been done:
When I bought the truck, not long ago, it had a P0135. It was stalling badly on every takeoff, but that was the only code I had. I replaced the upstream o2 sensor with a Bosch (now I know that was probably not a good idea). I found cracks on the exhaust manifold and exhaust smell in the cabin so I took it in. They replaced the exhaust manifold and also the thermostat (later found a code for that). Personally, I have cleaned the throttle body, replaced the spark plugs, replaced the fuel filter and air filter. I have also ran Techron through twice.
What codes do I have now:
Currently, I have the following codes: P0053, P0410, and P0455.
The truck is a 2003 4.2 I6 LT extended Trailblazer. I hope I have provided enough information and I look forward to your replies. Thanks again.