Can anybody tell me exactly what a pending code means? I was getting P0171/174/1172/1175 so I replaced the intake gaskets andcleared the codes, now I have P0171pd andP0174pd codes with no check engine light. Is the fault just not occuring enough to set the light on? Did it just occur once but it takes a long time to clear itself from memeory? Should I just erase it or does it need to go through enough drive cycles to clear itself from memorypermanently? Will it pass NY state inpection with these codes? I need to get in inspected soon, thanks.

 

I think a better term for them might be pending and prone to come back.
You either have a major vacuum leak or your MAF is about to go south.
What air filter are you using, how often do you change it?
Whatever you do, don't consider cleaning your MAF, it will kill it.

 

This has been a bit of a nightmare and I'm thinking it's the MAF now. My original codes were P0171/174 and P0734/733. I replaced the MAF and got the same codes. I also got the P01172/1175 codes, found a vacuum leak, fixed it (at least enough so that it holds 4 inches hgfor a few minutes - my vacuum pump sucks) and got only the lean and transmission codes again (with old and new MAF's).

Since I now have two MAF's I figured I would try cleaning the old one and see what happens. I cleaned it good with MAF cleaner and now I just have the two pending P0171/174 codes. I'm thinking that it's time to break down and buy another MAF. I have a paper filter.

 

So even after replacing the first MAF, you still have 2 lean codes.
Sounds like it is time to check for leaks all around the manifold.

 

The first thing I did was replace the MAF, it still gave me lean codes and a 4th gear code. Then I replaced the intake gasket after I found a small leak. That still didn't seem to help clear the codes. Then I cleaned my old MAF and now all I have are pending lean codes with no 4th gear. I assume that pending is at least better than setting the engine light, that is the closest I've come to fixing it. I hate to say it, but i think I bought a bad MAF.

 

[align=left]OBD II Pending Codes are also referred to as “continuous monitor� and “maturing codes�. An intermittent fault will cause the computer to store a pending code in memory. If the fault does not recur within 40 warm-up cycles, the code will be cleared from memory. If the fault recurs a specific number of times, the code will then mature into a diagnostic trouble code (DTC) and the MIL or “check engine� light will turn on.[/align]

So bascially the computer has detected something but will not turn on the CEL until it occurs over and over.But it also clear the code from pending status if it doesn't see the problem again for a specific amount of ignition cycles.

 

Hello all jkid Sorry for imposing in on your thread. I have a 2001 D2 and I am looking for a scanner that will enable to read the D2 fault codes. Could you please list the details of the scanner you are using? Thanks so much. Alon

 

Well, the place I got my MAF fromwas kind enough to send me a new one. I popped it in and I get a list of codes: P0171, P0174, P1172, P1175, P0103Pd. I then put my old (and now cleaned) Bosch MAF back in and I only get P0171Pd and P0174Pdwith no light. This is getting crazy,either Lucas MAF sensors have some major problems, I have horrible luck,or I have something else going on here likeO2 sensors. I think it's time to give in and take it to a shop. This is all sort of ridiculous because the truck runs justfine.