E300TD Mass Airflow Sensor Failure??
 

Hi all,

Just installed a K & N filter in my '99 E300TD yesterday. After about an hour of driving, the "check engine" light came on, and I have noticed now my boost pressure is MUCH slower building, though no other noticeable symptoms.

After reading through a couple threads, it seems the K & N MAY have allowed damage to the MAS??? Anybody else experience a similar failure with same symptoms? Any advice on a "stouter" MAS replacement?

(I'd like to keep the K & N filter if possible, as I noticed a little better throttle response and power UP UNTIL the check engine light came on and spoiled the fun!) Any help appreciated!!!

J.G.

The oil used on K&N style filters will coat the MAF sensor and cause it to malfunction.

New MAF time. (Oh, and I'd get rid of that K&N if I were you.)

Have you checked the codes to make sure the MAS is the problem. I've had a K&N filter on my E300 since it was new. My MAS went bad at 75K miles and I now have almost 95K with no problems. Just follow the directions on cleaning and reoiling. Too much oil is a bad thing in this case.

MAS are a R&R item on these cars and it seems 75-90K is all you can expect from them. Buy right here at Fastlane and save a ton over the dealer. Less than 10 min to install.

Good luck. :)

Thanks...going to check for a code tomorrow...and now find out why my fuel pump is leaking all over the place!

J.G.

Take electrical cleaner and spray a MIST on the sensor wires. DON'T SPRAY A JET AT THE WIRES. See if that helps. See the post: http://www.peachparts.com/shopforum/showthread.php?t=105816

I'll give the electrical cleaner spray fix a try tomorrow.

Many thanks!

J.G.

If you want to keep the K&N, here is a little info a friend of mine shared. Clean the filter thoroughly, just like you would do for a recharge, then spray only the outside of the filter with the recharge oil.

Dump the KN filter and get an afe filter, works a lot better and no oil.