The computer gives a code for MAF sensor, but I have replaced it. I unplugged it while it was running and it ran worse. I know its getting to rich a fuel mixture but I dont know why. I replaced the temp sensors, fuel pressure regulator, checked all vacuum (which the vac line to the egr had no vac, but i routed some to it and it ran worse), replace maf and tps. Is it possible that it is the computer? I do have an exhaust leak between head and manifold. I mechanic said that the o2 sensor would not cause it, and that an exhaust leak wouldnt cause it to run rich.
WHAT DO YOU THINK?
2007-07-05 13:27:58 · 3 answers · asked by Nicole g 1 in Cars & Transportation ➔ Car Makes ➔ Nissan
I replaced plugs, cap, and rotor.
With the truck running, I unplug the MAF and it idles up for 1 second and then way down and very rough. So, I figured both of the MAF sensors I tried that with were good. It is definately rich fuel smoke. Not oil. 132k miles.
2007-07-05 14:26:08 · update #1
Probably bad plugwires, or fouled plugs.
If that isn't the problem, then you may have a burned valve or valves. Check the plugs and wires first. If they are OK then do a compression test on each cylinder to check the integrity of the valves.
There is also the possibility of a broken oil ring or cylinder wall damage, which will cause the engine to smoke from oil blowby, which will foul the plug and cause the affected cylinder to missfire.
2007-07-05 13:50:38 · answer #1 · answered by Romeo 7 · 0⤊ 0⤋
Bull corn! Exhaust leak is causing the O2 sensor to think there is to much oxygen in the exhaust. Still throwing MAF code? you may have a wire broken near the maf sensor use a Volt OHM meter and see if you either have power or ground at the MAF plug at each wire key on. Poorly functioning O2 sensors can cause rich running . Lately I have seen lots of injectors fail. Mostly not squirting (not your problem) what is the fuel pressure doing? EGR works with a back pressure valve don't worry about that now. AND you are sure the engine is consuming to much fuel see and smell black smoke smell unburned fuel in the exhaust? Any emissions readings? How many miles on it?
2007-07-05 13:42:53 · answer #2 · answered by John Paul 7 · 0⤊ 1⤋
Did you check to see if you have a bad injector?
2007-07-05 13:42:15 · answer #3 · answered by Sexy Chick 1 · 0⤊ 1⤋