RProsser

Hey all. Got a problem with the wife's C280 (silver/dark leather '97 w/65K mi). We are about to head for Lake Powell for some water skiing and the damn check engine light has come on. First time for that. I suspect the light means the mass airflow sensor or one of the (rear?) 02 sensors, but would like to confirm first.

The nearest dealer wants $100+ to read the codes AND I have to drop it off. Jeez -- as if I don't spend enough $$ with them already!

I thought of AutoZone, but apparently, the stores here in California don't read codes any more.

So the question is: does anyone know for certain if any common auto part stores in SO CAL read codes while you wait?

I need to fix this right now. If they can't help me, I'll have to simply guess at what's wrong. More on that later.

Thanks in advance.

scorchie

You might want to check PepBoys. They either will do it or will rent you the scanner.

-s-

RProsser

Thanks.

I called a few of my local San Diego County Peb Boy shops. Only a few do it, and those have to make an appointment because the tech that does it is not always in. Oh, and it'll be $85 bucks. The dealer only costs a few bucks more than that. Still no way to get a fast diagnosis. I can't wait three days. Rats.

Wizo

Try the onboard diagnostics then post the codes you get.... also try the mercedesshop.com forums lots of good techs over there.

pks485

Most local garages can do it too. Try there.

Good Luck,

pks485

RProsser

Wizo, thanks bro. You too PKS.

Problem is, I don't have much time before I leave. Wizo, I don't know what you mean by "Try the onboard diagnostics" -- is there some kind of DIY utility on the car that I don't know about? I know tons about Porsche, but not near enough about MBZ. My bad.

For good measure, I pulled the MAS and sprayed some carb cleaner on the hot wire, then climbed under the car to inspect the two 02 sensors. Everything is intact. I fired up the car, and took it out for a romp. It runs great! In fact, it hauls *** for a 2.8! The light is still on, but it idles and shifts fine and I can't find a damn thing wrong with it.

Deductive reasoning: all the parts guys I spoke to today say the MAS is a regular sales item. It's a 3-minute replacement part. That's the upside. The downside is that the friggin' thing costs $250±! The same parts people I polled do not stock the front 02 sensor -- only the rear, so that tells me the rears go out often. The upside is that the cost is $125±. The downside is that it looks like a total pain in the @$$ to remove! It's in the middle of the "Y" at the back of the catalytic converter. How the heck are you supposed to get a wrench on THAT!?

Any ideas would be very much appreciated!

Wizo

The on-board diagnostics can be used if you have the climate control unit in your car... I can't remember how I did it. Do a search here and on mercedesshop.com and im sure you will find something.

RProsser

Nice to see you have 100K + on your car. That makes me feel better. I don't mind going through a few repair episodes as long as she'll go the long haul -- as a German car should! 65,000 miles is just broken-in for most older German cars. Maybe electonics are the downfall of the newer generation cars. Imagine owning a new AMG SL55 when it hits $150K! With all the electonics on that? It's not your grandfather's SL, that's for sure!

Wizo

Bob, the car has been good to me I have had only 2 major repairs and both could have been avoided. First my A/C compressor went out at 85,000miles. After looking at it the drain plug was leaking and all the compressor oil leaked out causing the failure. My second problem was the rear-end it had some problems but could have been avoided with less aggressive driving habits.

RProsser

Okay, got the error code checked at my local Union 76 station. They guy was going to give me a freebie, so I flipped him $25.

So here's the scoop on the CE light error code: 00171 or P0171, meaning "system too lean, bank 1" according to this MBZ OBD2 fault code manual

Now if I go to a different MBZ OBD2 error code link, it also adds "faulty mass air sensor" to the description.

Can anyone confirm this is the correct interpretation before I go out and spend $250 on a new MAS?

Thanks!

timecop369

I'm no expert but I think that was same error code when I replaced my MAS at 47K miles. After reseting the check engine light it's been fine.

I'd rather replace a $250 air mass meter w/ 3 min. worth of work than a $120 O2 sensor where you have to crawl underneath the car and take considerably more time and getting dirty.

Our cars are known for those bad Air Mass Meters.

Good Luck,

timecop369