SES P0170, P0430, P1174, P0173

[joegoodrich]

I've done some searching on the forum and found that many peopel have had problems with the SES light.

I've got a 2000 4.4 with 78K. I've been battling the SES for several months.

These are the codes I'm getting:
P0170 Fuel Trim Malfunction Bank 1
P0430 Catalyst Efficiency Below Threshold Bank2
P1174 Fuel Air Metering Manufact. Control
P0173 Fuel Trim Malfunction Bank 2

One of the threads refenced TSB SI B 12 07 04 that mention a deal reprogram to deal with SES light issues.

The vehicle runs perfectly, I'm not noticing any performance issues and it idles smooth.

I have removed the top cover to look at the crank case vent tubes, they look fairly new - I've had the vehicle 1 year so could have been changed by previous owner. If they were bad, I would expect them to look melted and I would expect to have a rough idle because of the vacuum leak.

Could this be a faulty MAP sensor? I have read posts about cleaning them, I'm not sure if it is worth a try.

Does anyone have access to a copy of the TSB mentioned above?

Or does anyone have any suggestions where to start first. For now I've cleared the codes, but I'm sure they will be back rather shortly.

I would like to try a few things before making the appointment at the stealer.

Thanks!

[NBX]

I have a 2000 X4.4i (77000 miles) and I was getting

P0170 Fuel Trim Malfunction Bank 1
P0173 Fuel Trim Malfunction Bank 2

I tried cleaning the MAF, I cleared the codes, but the codes returned a few miles later. Finally gave in and paid $240 for the MAF and replaced it. All is well - no codes. By the way, prior to these codes, I had already replaced the Oil separator top hoses. the other hose, behind engine block was ok.

Just in case, check all the plastic connections (hoses) between air filter box and throtle boby - some members have posted problems with cracked plastic hoses.


Hope this helps