Babbletron

I got a check engine light for the first time yeterday. Stuck the Vag-Tool on my car and picked up 17536 and 17538 (engine is running too lean.) So I UTFSE and started researching possibilities.

From what I read it could either be a leak or my MAF.

I then read up about checking for MAF flow. I used the measuring block 002 to see the MAF in g/s. I do not have a laptop. I just run a long serial cable from my desktop to my car in the garage. At first idle the MAF readout was reading 5.0 g/s and then as the car warmed up it dropped to about 4.5 at 760-800 rpm. I had my friend rev the car up to 2500 (the VAG program reads below the measuring block text something about IDle Values at 2500 rpm, I do not know what this means.) I looked at the g/s and they went up to like 13 or 14 g/s. I had him rev to 5000 rpm and the values went up considerably.

What I am wondering about is everything that I have been reading says MAF g/s is way up there like 300 g/s stock and can reach 364 g/s the RS4 MAF. I am guessing that these readings occur while driving because I couldn't get my g/s over 100 g/s at a stand still.

At idle the g/s according to Bentley should be 3- 4.5 g/s at I'm guessing idle. This is for a stock car. My APR chipped car is running at 4.5-5.0 g/s at idle. Is this abnormal or should it be reading higher?

Sounds like overall, people who throw these codes are replacing their MAF. If I do change my MAF does everybody here agree that I should change it to the Hitachi MAF?

How bad is to run your car under these conditions?

I guess I'll start there. ANy input will be greatly apreciated.

Dan

addìct

First, do some logs while driving the car. 3rd gear, low rpm to redline.

Since your a 2000, switching to a hitachi maf requires you to update your ECU to a 2001 program. Not really worth it unless you are planning to go stage 3.

Babbletron

I don't have a laptop. Can i borrow a laptop and stick my copy on their laptop?

Ochlockonee

Also you won't be seeing 300 g/s with a stage II a box car. With the Bosch expect around 220-240 g/s at wot near redline on the road. Typically the Bosch sensor reads too low when it goes.
Your best bet is to look for a torn tbb or f-hose. If these check out buy a new maf. They are so cheap and fail so much that I wouldn't spend much time diagnosing one.

addìct

yes.

EdyJun

Try clearing them and UNplug the MAF and go for a test run and see what happens.

Babbletron

I went and replaced the TBB with an AMS Kevlar boot, changed to 710N and replaced the f-hose. No noticable tears. I did note when I replaced the TBB that my snorkle clip right by the air box was missing. Not sure if that could be contributing.

I ran the car for about 20 miles and just like before the CEL came on and the same "lean" codes came up.

I went ahead and unplugged the MAF while I was at work. I don't have my VAG tool with me so I couldn't clear the code, but I did notice that the car ran much quicker just on the few test runs around the roads around my work.

If I clear the engine codes and run without my MAF won't the check engine codes come right back. Will they come back with some "MAF sensor missing code" or will it tell me that I am running too rich?

I am still planning on testing MAF values with my buddies laptop in the next few days. I am guessing that is now the MAF and just needs some replacing.

The only problem I have is that I want to drive 4 hours to Gainsville this weekend. COuld I drive without the MAF for this distance or would this be incredibly dumb?

DAn