scary codes P0170+P0173
 

96 M119 eng SL500,I have been having idle problems when hot only.
P0170+P0173 are left and right bank Fuel trim malfunctions.
Explanation is :self adaptation of fuel mixture "partial load"and or "closed throttle position" of rt and left cylinder bank at limit from engine control module (N3/10)
test step/remedy: 1)intake air leak
2)injectors
3)diaphram pressure regulator
4)ENGINE WEAR.
If I had a intake air leak would I have low Vacum?
would injectors throw faults p201 thru p208?
How to check Diaphram pressure regulator?
Engine wear?compression is good for 260K 180psi all 8cyl quiet running
Any help with where to start troubleshooting these codes and idle hot problem whould be appreciated John......................................:confused:

Ihave looked at the vacum lines,when I went to remove them for inspection they snapped like uncooked spagetti. Some of the rubber hose ends were so wiped out I was able to see thru them.
I have replaced the plastic hoses and the rubber hose connection ends and it seems to run better hot.:)
Upon inspection of the fuel press regulator I can smell fuel in the vacum hose hooked to it. so I hooked up a long section of hose to it and pulled vacum you can get a slight smell and taste of fuel but no liquid should I replace the regulator???:confused: Thanx John.........................

About 95% of fuel trim codes are related to an air mass sensor that doesn't return the correct info on the amount of air that is going thru the sensor.

The other 5% are either vacuum leaks or the fuel pressure/ regulator.

I replaced the MAF when I got that code a couple of months ago it was code P0100,reset it never came back so replacing the MAF fixed that.
I also had code P0410 secondary air injection system,but all the components checked ok fixing the vacum leaks have cured this problem so far looks good.

I am going to change the fuel press regulator this week.I dont like the fact that there is a fuel smell+taste comming from its vacume line no liquid but at 259K I am sure it is due. for $36 bucks its alot cheaper than the MAF I replaced.

I have replaced all the vacum lines(wow they were shot) and also the Fuel press regulator.
Now to get the fuel trim to go back to some kind of starting point do I have to disconect the battery???
Or will it self adjust in the other direction away from its limit.
I have erased the codes with the mt2500. I will drive the car to work tonight and see if the codes are gone tomorrow. I really hate disconecting the battery on this car it is like starting from scratch with everything

Well after a few days of driving the mil came on and the same codes are back after all the vacum lines were replaced along with the plugs, MAF,faulty O2 sensor ,and Fuel pressure regulator. I have disconected the battery and will drive it again. Lets see what happens??????:confused:

dont buy cheap ebay MAF
 

turns out to be the new $90.00 ebay maf was bad! my old maf was totaly shot it had an open circuit. so I shopped around and got one off ebay, thinking I fixed that problem I continued on to my other dtc codes but could never get the fuel trim codes to clear. I replaced all possible items such as fuel press reg, vacum lines, intake gaskets and so on finaly changed the maf again with the proper bosch factory one and all is well with the M119. thanx for all the good info guys:D