99 Century Problems,

Check Engine light came on Friday night, would not start untill car cooled down. Once cool it started but was very hesitant and missed very badly. Seems as car gets more to operating temperature the problem becomes more evident. Took the car in to Advanced to have the Check Engine light diagnosed which came back with 2 codes,
PO171-PCM detected the fuel system for bank 1 was too lean
1-If bank one and two codes set togeather suspect fuel pressure or MAF (mass air flow) Sensor.
2-Oxygen sensor defective
3-Ignition misfire-repair
4-Fuel Injector Problem
PO300-Multiple random misfires have occured
1-Ignition system fault-spark plug(s), ignition wires, coil,
2-Vacuum leak
3-injector fault
4-High or low fuel pressure
I bought one coil pack and moved it to each of the 3 locations and did not find a change in performace. I'm about to try the fuel filter.
If any one has any possible Ideas they have seen before associated with this problem please write back, no suggestion will be scrutinized.

Thanks
-E

Welcome to AF, check fuel pressure at the rail, basic diagnostics before any parts are replaced. Was any recent engine work done?

Nothing other then oil changes is there a simple way to check the fuel pressure at the rail?

Don't what is simple here, but you need a fuel press. gage attached to the port on the fuel rail. Look for 40 psi.

I have a friend of a friend running the test tomorrow, what are the options if its 40PSI or not?

He said the fuel pressure was good, told me to change the mass air flow sensor.:banghead:

Hope this works, normally the maf will set a code, look for air leaks behind the maf if there is ducting from the maf to the throttle body.

didn't change the maf went and got some choke and throttle body cleaner, cleaned the choke and air intake sprayed it down very well, let it dry and fired her up. Service engine soon light was gone but still have a misfire? Messed up on the plug wires?

From here your guess is as good as mine recheck the firing order, what else?

nope not firing order, and the light came back.

the module is fried. I guess all Canadien models 3.1 Engine code M have issue's with this.

For any one else who runs into this problem be very carefull. Don't go off half cocked replacing every part accesible by you under your hood.(I did that) Take it in and have the diagnostics ran like I did after my own tune up. Came back as three faulty sensors one of which I blew out with Ether. The MAF sensor is what I trashed with the ether. The TPS was bad and the MAP sensor was also bad all fairly easy fixes. The tech who worked on my car could not give me an explanation for the two going at the same time but stated there was a possibility that the added work load on the MAP sensor after the TPS sensor went out could have caused it to go bad. Then the next condition was a bad Fuel pump. Just like said at the beginning check the fuel pressure at the rail. Mine read out at 8 psi and could barely run. Now she runs great again. Thanks for every ones help.:cool: