fastneutron

I pulled codes P0170 and P0173 on my C43 using my handheld OBDII reader. The CEL came back on after 500 miles from clearing it the first time by changing the Bank2 Sensor 2 O2 sensor. I took the MAF sensor off and could not find anything wrong. The MAF sensor was actually just changed 8,000 miles ago because the last one got damaged by the fluid from the aftermarket air filter. My mechanic (Chino Hills AutoHaus) told me that it could be that I didn't change the other 3 O2 sensors and they are nowlagging as far as response compared to the one I changed out 500 miles ago. It sounds like a myth to me. If they were also bad then the computer should have also indicated that. My mechanic thinks that my OBDII reader doesn't give as much detail.

Could he be right? My car is now over 100K because of commuting from LA to San Jose. I just don't see changing something that it is still okay, especially because of the labor and cost involved with changing the O2 sensors.

I've already reset the P0170 and P0173 once and it came back on again after driving from Ontario Airport. Supposedly, my MAF sensor should be covered for at least 1 year or 20K miles warranty, but I'm not going to take it to the mechanic if he'll just tell me to change the rest of the O2 sensors although it is not necessary.

I might just try and clean the MAF sensor with intake/throttle body cleaner by STP.

steve s

u probably do already, but what do the P0170 and P0173 codes mean?

linuxfoo

your P0170 is most likely your MAS sensor, i saw that you said that it was previously replaced like 8k ago, however if you are still using aftermarket filters such as K&N that is overly oiled, then your MAS sensor will go out again. instead of using a throttle body cleaner, try using a carb cleaner first and then followed by brake cleaner. but take out the MAS when you do this, instead of spraying the liquid into the throttle chamber.

i believe carb cleaner a bit stronger than the throttle body cleaner and the brake cleaner will rinse off all the residue and dry it clean. i would try this before you buy anything, because what do you have to lose.

fastneutron

I'm going to swap out the MAF with my other C43 to really find out if it is the MAF.

I learned that there are two versions of the MAF that the dealers cary in their inventory. The older version is for approximately $280 and the latest version is $ 450. MB must be aware of the failures of the MAFs

I'm just hoping that the last time I had the mechanic change out the MAF, he really did change it with a new part and not just cleaned off the residue from the aftermarket air filter. I've had stock air filter since the last failure of the MAF. So, I 'm curious if the mechanic didn't screw me over and didn't really replace the MAF.

We shall see.