I was just driving it about three hours ago then the check engine light flipped on at a light still drove all the way home shut it off then I waited I started it again fine I thought but check engine light was still on then I go inside three hours pass get in to start and it won't start but it cranks. So my question is. Would this be the mass air flow sensor or the crankshaft sensor or maybe even something else and help is appreciated. Thanks for reading!! Oh yea doing it myself so maybe an idea of level of difficulty

Newer cars like yours are capable of telling you what is wrong simply by reading the DTC with a code reader. A DTC is a Diagnostic Trouble Code.

Auto parts stores may loan a code reader to you.

Also be sure to keep your battery charged (if not starting) by connecting a battery charger to it.

Nino, from my experience a bad MAF sensor will cause the Check Engine warning light to come on, but will not prevent the engine from starting. So you must have another problem. As Elektri recommends, you should read the DTC's before throwing parts at the problem or guessing what's wrong.

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Fred Hoelzle

Alright will do I will post back

I for got to say I got up for work dis morning went out to the car and it started so any ideas from that? Anything will help thanks .

Put a crank sensor in it, you can test by hooking up ohm meter and heating up sensor to about 200 degress see if reading goes open

I got a scanner told me the crank position sensor and intake manifold sensor and a vacuum leak

Thanks for the heads up about using a scanner haha easy taking her to the shop tomorrow. Anyone know how much money I'm gonna be looking at? Cps and the map sensor and a egr valve and a tune up and fix the vacuum leak? Just wanna know what I'm looking at I'm a new Benz owner I love my car just wanna take care of her.

I just did a Crank Position sensor on our 2002 CLK320. Taking it to a shop, figure about $175 for the sensor and 1.5 hours labor. It took me close to a full 1.5 hours to replace...it is a tight fit between the back of the head/block and the firewall, plus the firewall is apparently has razor blades built in , lots of sharp stuff there.

Betting you just need new vacuum lines to the MAP, switchover valve and EGR (but might have a clogged EGR tube too).

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Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

It is worth the gamble to go buy a CPS sensor at(only option on Sunday) Autozone here in the USA for 50 dollars, and change it your self...

Five minute job. You can even do it with a SAE 5/16" 6-point socket 1/4" drive socket..

better than 95% that is your problem..

PeachPartsWiki: R&R of the Crankshaft Position Sensor

The other 5% can be the fuel pump is dead, but you can press on the sharader valve on the fuel rail, and watch the fuel squirt out-not dribble out..

Both are easy, you may need a flash light to find the sensor. It is at the rear of the engine on the drivers side..

Best of luck,

Martin