Anyone care to lend code help to a recent DIY convert?

[Meisterbr?wn]

Subject: 2000 DII with 60,995 mi.

I just got a code reader at lunch to check what was causing the SES light. This is what I found:

P0174 System Too Lean (Bank 2)
P1175 Lambda control adaption fault bank 2.Last occurrence - minimum signal
P0171 System Too Lean (Bank 1)
P1172 System Too Rich, Bank A & Bank B

Now a little over a week ago I took the rig to the dealer for my SES light, the invoice says they pulled 4 codes but only listed P0171 and P0174. Dealer said it was a bad MAF because of a cracked air box (I won't go into how I am unable to find a crack in my airbox, that's another thread). They cleared the codes and it's been SES-free for the last 10 days, until it came back last night.

Question for those in the know: do those codes sound like a MAF going out? I'm new at this and those descriptions migh as well be Greek. Reading other threads indicates I might be able to squeeze a little more life out of the MAF by removing it and cleaning with electronics cleaner - going to try that tonight.

Thanks for any advice.

 

[Jay B]

I have practically the same vehicle, and it has been doing the exact same thing as yours since about 60,000 miles. It would set those codes at about 1 - 2 weeks after clearing them. Eventually, it would set them every time I drove it. I was advised to replace my spark plug wires (plugs were new). It seems that poor combustion can cause false readings from the Lambda system. Getting codes indicating both too lean and too rich doesn't make much sense. After replacing the wires, the light stayed off for about a month. It came on once, after a long, high-speed road trip, a short rest, and a hot start. This time it's only the too-lean codes. I probably need to replace the oxygen sensors, but if it only sets codes once a month, I can probably live with it. Anyway, it looks like replacing the plug wires goes a long way toward keeping the SES light out. I would NOT try cleaning the MAF with any kind of solvent. If someone else on this board knows that it's OK to do, then I hope they'll correct me.

 

[Nori]

Well if you use the "Search" you will find almost the exact same situation threads out there. Actually I cleaned my MAF sensor last week end with a Electrial Parts cleaner that I got from Pepboys.
It works great, and gets it very clean.


Just look though this web sight and you will find many things.
Actually so many similar leads.

 

[Nori]

All you have to do is click on the Search and type in the code number.
Then you will get dosens of things.

 

[Nori]

Well I had the same code few weeks ago, first I found out the Air filter cover was not on correctlly, and also i found out that the O-Ring for the MAF had snap'd and was lying on the frame in the engine compartment.
Well since I was changing the O-Ring, I went a head and clean'd the MAF too.
After that I have not had any problems for several weeks.
I am also planning to change the Plug Wires to Magnacor next week end.

Hope this will help.

 

[Meisterbr?wn]

Thanks Nori and Jay -
I did a search and only came up with 4 results (1 of which was this thread). If you've found other information, let me know.

I did the 60k service last October myself with the help of a qualified friend. We changed the plugs and wires (the wires were a huge bitch). I'll go around and check connections tonight.

I plan to remove the MAF in the morning and clean it with electronics cleaner per this link:
http://www.discoweb.org/forums/showthread.php?t=1201

It looks like the MAF isn't a terribly expensive part, so replacing it eventually won't be terrible. It's the other two codes that concern me (1175 & 1172)

 

[Nori]

Your MAF might be going bad or is too durty.
When I took my MAF off, I had to move my car a little and I think I got the same code.
You might want to clean the MAF first and then see if you get the same reading.
Oh, make sure that MAF O-ring is in there. If you do it in the dark at night you wont even notice that it even fell out and you will get the code again.

Good luck

 

[Jay B]

It may be O2 sensor time for both of us! It wouldn't be so bad, but there's four of them!

After writing the above message, I checked the link you suggested on cleaning the MAF. That's really interesting! I'm going to try it tomorrow. My wife's Volvo has a burn-off feature in the MAF that works like a self-cleaning oven. Good idea, but the thing costs $400 when it goes! You can buy a lot of solvent for that kind of money!

 

[Meisterbr?wn]

Hey Jay -
I cleared all the codes Friday afternoon and took her on a 100mile freeway trip Friday nighy. As I pulled on the highway (after stopping for gas) about 25 miles into the trip, the SES light came back on. Saturday morning I checked the codes and got P0171, P0174 and another one, can't remember the exact code, but it was something like: implausable 4th gear ratio. Anyway, after checking that code on Dweb I found that it was common to a bad MAF (not sure the relation, but whatever). Yesteraday morning I removed the MAF and cleaned it with the electronics cleaner (the MAF and both electrical connections). So far so good. I put another 100 miles or so on her with no issues and am going to be doing the same today. I don't think this solved my problem, but if I've bought some time, that's good for me.

The O2 sensors are my next bet, but I'll need to narrow it down more.

Good luck with yours, let me know how it turns out.