Having problems with a '93 crown vic. The car starts and idles fine and drives alright with one exception, if you mash down on the pedal it boggs down both from a stop and once your already moving. If you ease into the pedal it drives alright, sometimes still hestitaes getting up to speed.

I have replaced the EGR Valve, tube connecting EGR to exhaust, and the differential pressure feedback sensor. I have scanned the codes and both the key on engine off and key on engine running cleared fine, but I have three continuous memory codes. 172 - HEGO (HO2S) sensor fault/lean, 176 - HEGO (HO2S) sensor fault/always lean and 634 - manual lever position sensor voltage higher or lower than expected or A/C on.

What and where is this manual lever position sensor? Or is there something else I ought to check? I appreciate any help in this matter, I have used this site to find solutions to problems with my powerstroke before and it's been right each time (cam position sensor, vacuum pump for bad braking, etc.)

 

Welcome to the forum

The lean conditions could be caused from a dirty MAF sensor. I'm not sure what a lever position sensor is either unless it is refering to the TPS sensor.

 

I'm having the same problem with my 4.6L but mine is in a 2002 F-150. When you mash on it is hesitates and then after it thinks about it for a second it decides to move. I've driven other peoples trucks from V6 to the 5.4L V8 and I am really disappointed in the 4.6L I own. Any suggestions on throttle response? I've cleaned the MAS and it doesn't perform any better. I have an Airaid intake system, Flowmaster exhaust and a Hypertech Programmer. I notice gains once the thing is rolling but off the line it's still a dog, even with the mods. Help us anyone!!

 

I would be looking at plugged cats...

 

Call me ignorant, but what are plugged cats?

 

The manual lever position sensor tells the computer the position of the column shifter (1,2,etc) On the AODE/4r70w transmissions, it's located on the driver's side of the transmission just above the pan. The sensor has a black plastic cover riveted to a metal body and a gray electrical connector on the aft edge.

I think that there was an upgraded sensor with a better seal for 95, the older ones (91-94) have a reputation for bad seals.

 

catalytic converter in the exhaust system

 

That is commonly know as the neutral safety switch or gear selector switch. That's what threw me off on the lever postion thing.

 

Yea that manual lever position sensor is also the neutral position sensor, I did find out that the code read for that could also be the throttle position sensor. So I replaced the TPS, cleared the code but didn't fix the problem.

Is there any way to check for a plugged cat? The car has four cats and I would hate to put $500 or more into replacing the cats and it not be the problem. Although a friend of mine had a '96 crown vic that the cats went bad on, different symptons than mine though. I'll also look into cleaning the MAF sensor. I'll keep you posted, thanks for the help thus far.

 

i have a 1994 crown vic and i have put a brand new motor in it and i have notice latly that i have alot of problems with it. its the 2nd motor i got for it and the first one i broke something off in the combustion chamber and messed that one all up and sent it back and got a new one but this new one ran real good for a while but then i notice when the motor was cold it would stumble and shut off as i would try to go. i looked into it and the best thing i found out would be the tps but i never replaced it and it dont do it nomore. but this morning i had a bad problem i would start goin them it seems like the motor loses all power and just putts along. then i drove back to the house and it started working ok then went to school fine the whole way fine the whold way back then got back in it a few hours later and it was tapping on the back side of the driver value cover. which i had the problem before once for running bad gas and some other ****. but i was thinking my fuel filter was clogged up cause the motor to stumble and something else causeing the tapping cause this is my car to get back and forth to school so i need it all the time. oh yea and for everyone who thinks the cop car crown vic aint fast ya are crazy. stock nothing done to it and it will run 130-135 easy maybe it just me but i reckon thats fast enough. Beats Chevys All Day Long ... but if anyone has any info to help me out i could use it

 

I got my '93 crown vic running fine now. The cats tested fine so I replaced the fuel pump. It ran better but not 100%. I had some Bosch spark plugs in it and with advise from a mechanic replaced with Autolites and that helped it but still not all there. The final item that was replaced was the mass airflow sensor. I couldn't tell you if it was the MAF the whole time as I replaced parts in the order above, but it runs strong now.