MJumpman42

I have an 01' SES Taurus just the 12 valve 3.0L V6. It has sat for about 6 months, with me occasionally starting it, until this past August when I decided to get it registered. I have recently changed the steering pump, EGR valve sensor and tubes, and had the oil changed when shortly after, about a week, it began to sputter and give lose power/ability to accelerate. The car runs fine for the first 10-15 minutes then it slowly begins to give me issues. The problem progressively gets worse until the car will eventually die. The check engine light came on and I got the codes po174 and po171. Unfortunately I sought the assistance of Auto Zones employees and replaced my MAF sensor and o2 sensors to no avail. Any hints as to what to check? I appreciate your time and assistance.

Bert

They have been known to have vacuum leaks causing those codes. Here's where you may find your answer. codes p0171 p0174. Rough Idle / engine light on

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Bert

MJumpman42

I checked for a leak and took it to my buddy's shop and we couldnt find any kind of intake leak.

After starting it cold this morning it still does the same thing. Drives great for 10-15 miles, or until it gets really hot, then begins to stutter just a little bit progressively getting worse until the car will not function at all. Any other ideas?

Oh I also changed the PSV vale and hose, to no avail.

CatSkinner

Finding a vacuum leak is tough. The better method is checking the actual vacuum. If you have lean O2's and vacuum is low, you have a leak. If vacuum is normal, you probably have a fuel delivery problem.

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Prius repellant, just add gas.

MJumpman42

K I apologize that this slipped my attention before but I guess my coolant reservoir is cracked and when the car heats up it begins to spray albeit a small spray of coolant. Could this be causing the aforementioned problem?

I will check the vacuum today.

R.S.LOGAN

Could cause problems if spraying over any electrics , plugs, leads , coils etc and causing tracking .

MJumpman42

I took my car to a mechanic today, a friend of mine, and we hooked his computer up to the car and took it out for a drive. We drove around for about 30 minutes before the problem started to happen again. While the car was progressively getting worse the p0174, p0171, and a p0122 TPS error code all came up. I do not want to just change the TPS if it is just going to be another $60 down the tubes.

He did a thourough vacuum leak check and found nothing. I appreciate all of the help and advice given already, just wondering if a faulty TPS could cause these issues after it driving fine for 20-25 minutes.

CatSkinner

To add to R.S.Logan's entry, if the coolant is shorting the signal buss for the sensors, the output could drop which will cause the return signal to drop as well. The TPS and O2 sensors run under a pretty tight band, so they could be affected first. Get the leak fixed and apply some electronic cleaner to the connections.

Did the mechanic throw a vacuum gauge on the manifold?

__________________
Prius repellant, just add gas.

MJumpman42

Turns out the mechanic did not change the rear O2 sensor. So that is next on the docket and replacing the coolant tank.

I will post with an update. I appreciate all the help and advice.

MJumpman42

I have changed all four o2 sensors, and changed my cracked coolant tank. The weather has since turned colder and I have not had the problem since Friday when the colder temperatures arrived. Any other ideas, because I fear I am still looking at this problem reoccurring.