Misfire and codes

[SHO_Times]

the last few weeks Ive been having a misfiring/stumbling problem. I only feel the misfire when I am going at least 45-50 MPH. Today I stopped at autozone and bought a 30 dollar scan tool. I hooked it up and gotten codes

124- TPS voltage higher than normal
172 bank 1 lean
173 bank 1 rich
176 bank 2 lean
177 bank 2 rich
543 fuel pump circuit open connection

Any ideas on what my problem could be?

By the way I have a 94 taurus SHO 3.2 I just hit about 100K on her. Owned by an old man who took really good care of her, but not sure he did much maintenence on it besides changing the oil.

 

[riden2low]

http://www.shophoenixproject.com/
Go here for the codes. But it looks like it may be time to change out the oxygen sensors. 60K is in order too. I just went thru mine doing 60k and bearings. Plus I took off the intake and had to totally clean that up. The EGR tube in the intake was real gunked up bad. Now it is a happy engine. I just joined the group here not too long ago and they know what they are talking about. They helped me get my SHO back on the road.

 

[luigisho]

Change the throttle position sensor, clear the codes, and see if the codes return. When's the last time you changes plugs/wires?

 

[jmpSHO2nd]

I don't think I ever saw all those lean/rich codes at the same time. Replace TPS and clean MAF and see if they return.

 

[rubydist]

543 just means that the engine stalled at some point, and almost always can be ignored.

the tps code needs to be addressed, because these engines will run stupid if the tps is bad.

once that is taken care of, then you can determine if the o2 sensors are bad or not. if they are original, most likely they need replaced.

 

[lowc]

if lean codes come back check for vac leak at intake

 

[projectSHO89]

Simultaneous lean/rich codes usually means a bad O2 sensor (per bank).

But... Proper testing and repair protocol prescribes that the code that is issued first by the PCM should be addressed first as there can be a cascade-like chain of reported faults.

So, fix the TPS fault first, reset, and retest to see if additional faults are still present.