Hi all.
Total newbie here. So apologies in advance for the lack of knowledge. I have a 2004 C320 with approx. 158,000 miles. I am getting a Check Engine Light when I reach 40-45 MPH when accelerating onto the highway into the flow of traffic putting a moderate but not super heavy load on the engine (without AC running). My OBDII reader is showing misfire codes P0302 and sometimes P0306. Never got codes for the other cylinders or any other codes at all. Always just the misfires. I pull over and clear the code and turn the car off and back on and it ran normally again until I needed to accelerate back onto the highway. I changed all the spark plugs, wires, coil packs and fuel injectors. It hasn't thrown the codes in a day or two but still sounds a bit "grumbly" like it's about to misfire again between 40-50 MPH while accelerating. I was reading the data on my OBDII scanner and noticed the timing advance is showing -17 degrees at idle and would go to approx. -33 when I rev the engine. Is that a normal reading? After some google searches all the other OBDII readings looked like they were in normal range.
Thanks in advance for any advice.
Total newbie here. So apologies in advance for the lack of knowledge. I have a 2004 C320 with approx. 158,000 miles. I am getting a Check Engine Light when I reach 40-45 MPH when accelerating onto the highway into the flow of traffic putting a moderate but not super heavy load on the engine (without AC running). My OBDII reader is showing misfire codes P0302 and sometimes P0306. Never got codes for the other cylinders or any other codes at all. Always just the misfires. I pull over and clear the code and turn the car off and back on and it ran normally again until I needed to accelerate back onto the highway. I changed all the spark plugs, wires, coil packs and fuel injectors. It hasn't thrown the codes in a day or two but still sounds a bit "grumbly" like it's about to misfire again between 40-50 MPH while accelerating. I was reading the data on my OBDII scanner and noticed the timing advance is showing -17 degrees at idle and would go to approx. -33 when I rev the engine. Is that a normal reading? After some google searches all the other OBDII readings looked like they were in normal range.
Thanks in advance for any advice.
