6 trouble codes, most ever
 

Update on previous message.
My 2000 ML320 65,000 miles has a intermittent trouble, when I start it cold it's ok. But one time during a 3-4 week period it will start and idle rough, has no power when I put it in drive, but if I turn it off and back on it's fine. Had someone put a code checker on it and it read
P170, P173, P300, P304, P305 and P306. That was the most codes he had read on any truck.
I have had all the service work kept up. What's the trouble?
Thanks Ron.

300's are miss fire cylinder numbers....300 being Random Missfire....170 and 173 are fuel/adaption codes...when there's an adaption erase..ie: when someone erases all adaption stratagies...the miss fire's come along next as a rule.

Are you sure he did not do anything else other than collect the codes ?
The engine often gets miss fires from faulty plug resistors and plugs coils too.


.

Most common failure for the adaptation is the AIR MASS SENSOR... 98.5% of the time..

If the mixture is "leaned" out then the misfires will follow...

OF course the left catalyst could have blockage causing the misfires if the mixture was VERY lean & the catalyst melted!

Doc is right..Mass air flow sensor is most replaced item.....sometimes when it's not faulty .

Pull all the plugs/coils/resistors....check for flashover and worn plugs.
Call your local parts dept' and ask them how many MAF's they have sold recently.
It will give you an idea of the failure rate.
Pity you don't have a scan tool to check the a/f learn adaption.



.