Got a Check engine light on a 01 S430 and I pulled the codes it has a p0170 and p0173. I pulled the mass air and cleaned it and checked for vacume leaks. Any other advise on which direction I should be looking?

 

Cancelled the codes? or been thru about 3 drive cycles?
Codes reappeared? CEL still on?

Mileage 75k miles upward?

Signature is 99.5% MAF.

Cleaning does not always work.

Sure your motor is up to date on Service. Plugs? filters etc

If you decide to change the MAF (not sure you have any other option) I personally recommend using a Genuine MB or at least the correct Bosch one.
Other after market sensors can give strange results. Some people swear by hem since they are much cheaper but I'm not convinced in the long term that they are the best route.
Choice is yours.

Stuart

 

The car has 87k on it always been serviced at the dealership, I will have to get the records to see what has been done. It is idling a little rough. Cancelled all codes and they came back in about 10 miles. I figured MA but was hoping there was something I was missing that would be a cheaper fix

 

87k. Yep its the MAF.

Moderately expensive maybe but if you do it yourself (very easy job) you will be so pleased with the results (improved gas consumption, cleaner better acceleration and smooth tick-over) that you will think it was worth it.

Stuart

 

Thanks guess I'll visit the stealership tomorrow and pick one up.

 

Welp on the way home today the CEL went off, cross my fingers that it will stay off for a while.

 

If the CEL gone off after about 3 cycles it looks like your MAF cleaning did the trick.
A cleaned MAF won't last as long as a "new" one but should give you a good extension before it requires changing.

Stuart