Hi just got a 1998 mark VIII 68000 miles Codes PO171 & PO174 I think it bank 1 & 2 lean is this the 02 sensors I have no idea if they have ever been changed. Thanks for your help. Also it seems to run good but if you stomp on it it falls on it face any ideas. thanks again jim
mark VIII 02 sensors?
- Thread starter azjim
- Start date
I see there are 2 up stream and 2 down stream do all 4 have to be changed at the same time also rock auto are about half price whitch ones do you sugest thanks azjim
Lownslowlsc
Dedicated LVC Member
The front 2 would be the most common to go, the rear 2 just monitor how the cat's are doing.
Try cleaning the maf?
Try cleaning the maf?
Lownslowlsc
Dedicated LVC Member
Yeah, un screw the 2 clamps for the intake tube, 1 at the manifold and 1 at the air box. Remove 4 bolts holding the air box together and disconnect the maf connector. Go to a auto parts joint and pick up maf cleaner, I belive crc makes some. Spray the heck out of the leads in the maf till they're nice n' clean. Do not touch the leads as they are very fragile. let dry and reinstall.
I'm not positive this could be part of your prob but it's worth a try anyways. Dirty mafs aren't happy maf's.
I'm not positive this could be part of your prob but it's worth a try anyways. Dirty mafs aren't happy maf's.
87TTOPGT420
Dedicated LVC Member
Also check for broken vacuum lines
Lownslowlsc
Dedicated LVC Member
Yeah, check the ones on top of the manifold at that T. I had 1 that cracked/collapsed but still sealed and didn't cause any drivability issues. Worth a check anyways.
My Great 8
Dedicated LVC Member
You nailed it! My 98 had the same problem. Bought the CRC MAF cleaner and it runs perfect with no CEL. My neighbor has a 95 Town Car and I did the same thing with the same result. Welcome to LVC!
chris2523
93 Mark VIII
lean codes on both sides indicate an actual lean condition. your o2s work fine. find what's making it run lean.
clean the mar, CRC makes a great cleaner in a gray aerosol can, and check your vac lines.
clean the mar, CRC makes a great cleaner in a gray aerosol can, and check your vac lines.
well I have put on a new fuel filter and cleaned the maf runs better gas milage at 18.7 from 18 and just code PO 174 bank 2 lean would this be the o2 sensor thanks for all your help