gerald holland
Member
I have a 2000 Expedition with the 4.6 engine. It was running good but when I tried to smog it there were codes that showed up. The codes for Lean on bank 1 and 2, EGR flow no good. I first cleaned the MAF sensor and checked for vacuum leaks with a smoke machine. Then I removed and cleaned the throttle body assembly and installed a new fuel filter, #7 spark plug and Fuel pressure releif valve and had to install a new battery. After I put it all back together it ran good for a few miles and then started to mis-fire. So I installed a new coil on #7 cylinder.
The mis-fire got worse and I read the codes again. Now I had the following codes -
P0136
P0156
P1131
P1151
P0308
I cleared the codes and it ran good for a few miles, then started to mis-fire. It got worse. I cleared the codes again and then after driving a ways, up came codes about the 4 O2 sensors but no codes re the misfire. I cleared the codes again and now it runs fine in the driveway. I will try the road tomorrow. My main question is why does it run good after I clear the codes but after a mile it starts to mis-fire again?
thanks, Jerry
The mis-fire got worse and I read the codes again. Now I had the following codes -
P0136
P0156
P1131
P1151
P0308
I cleared the codes and it ran good for a few miles, then started to mis-fire. It got worse. I cleared the codes again and then after driving a ways, up came codes about the 4 O2 sensors but no codes re the misfire. I cleared the codes again and now it runs fine in the driveway. I will try the road tomorrow. My main question is why does it run good after I clear the codes but after a mile it starts to mis-fire again?
thanks, Jerry