99 Taco engine pigging out

sololight · #1 (**permalink**) 02-29-2008, 06:54 PM

v6/standard, check engine light codes to PO171.
I have changed both O2 sensors, cleaned the MAF sensor and it still bogs at all speeds as well as idles up and down. Should I replace the MAF? Catalytic converter plugged?
Solo

The Phoenix · #2 (**permalink**) 02-29-2008, 08:42 PM

If you don't have a supercharger, I would rule out clogged cats. Injectors could be dirty. How many miles on it?

sololight · #3 (**permalink**) 03-01-2008, 05:15 AM

182,000.

The Phoenix · #4 (**permalink**) 03-01-2008, 08:24 AM

Try some fuel injector cleaner. Cheap way to rule it out.

sololight · #5 (**permalink**) 03-04-2008, 06:20 PM

Thanks for replying Phoenix. I've run 2 tanks with injector cleaner - no change. I can not hear of visually see any vacuum leaks. PCV valve and hose check out. Coolant temp gauge operating normal. The engine idles up and down and sometimes stalls when cold. When on the move it bogs when I step on the fuel and put it under load. It gets better as the truck warms up.
Any other thoughts?
Solo

The Phoenix · #6 (**permalink**) 03-04-2008, 08:24 PM

I'm pretty stumped. The cats were not my initial thoughts of what would be wrong, but it's possible.

integraGSR · #7 (**permalink**) 03-08-2008, 06:45 PM

p0171 i believe is system too lean. MAF sensor us taking a shhit. if you clean it, it will work, but the code will come back. and if you clean it again, it will come back on quicker every time you do it. soon you will just have to replace it.

sololight · #8 (**permalink**) 03-08-2008, 07:11 PM

The symptoms have gotten worse. I am going to replace the MAF sensor and see what happens. I'll let you know. thanks

sololight · #9 (**permalink**) 03-10-2008, 06:16 PM

I installed a brand new MAF sensor and the truck runs like a top!
FYI ... I found it much easier to remove the air box to get to the sensor rather than try to mess around with a 90* screw driver in a tight spot....
Thanks for the help.
solo