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Series of problems. Please help.

Nick Buol

New CEG'er
Joined
Jul 12, 2004
Messages
20
Location
Pleasant Hill, IA
My 1999 Contour SE Sport (2.5L) has been the most problem ridden car I have ever owned, yet I love to drive the sucker....

Anyway, my CEL came on (again) about 4 weeks ago. Typical P0171 and P0174. Last time they came on, it was new O2 sensors all around. That was about 9 months ago. So I clear the codes and let it go for the time being to see if the same codes come up again.

Well, they did this weekend, but I didn't get a chance to get them read until today.

Today's reading shows P0171, P0174 AND P0460 (Fuel Level Sensor A Circuit Malfunction).

Hmm. The gas gauge seems accurate.

Anyway, yesterday morning, I went out to start the car (cold morning) and it started fine, but then the RPMs dropped to about 400 and the car stalled. Never happened before. I start it back up, and give it a few revs. Let off the gas, it slows down again, and starts to stall.

When driving, it is fine. I just watched it at stop lights and gave it a gentle touch of gas while braking, and made it to work OK.

I am thinking vacuum problem possibly? But I am looking to the more experienced experts here.

Some other key data. 79K miles.
Like I said, new O2 sensors less than a year ago, new fuel pump 2.5 years ago, new alternator this summer...

I was told by ProjectSHO89 here that I shouldn't be surprised if the P0171 and P0174 codes come back after the "professional" diagnostic (and O2 sensor replacement earlier this year) because they don't diagnose vacuum issues.

So. Ideas? I am going to check for vacuum leaks tonight (I am sure that I can find a sure fire way to do that), but I am still wondering about the P0460 as well...
 
A vacuum leak would definetely give those codes since unmetered air is being pulled in after the MAF and cause the rough idle/stalling issues.

Not really sure about the fuel level though.
 
A vacuum leak would definetely give those codes since unmetered air is being pulled in after the MAF and cause the rough idle/stalling issues.

So, check "accordian" hoses for leaks, tape if needed? Spray carb cleaner on other hoses, listen for change in RPM and replace as needed?

Right? I've never done a real "vacuum check" before.

Nick
 
Check the accordion tube, TB gasket, UIM and LIM gaskets, IAC gasket, etc. Im guessing if its causing your car to stall, you can probably hear it by poking your head underneath the hood.

The UIM and LIM gaskets can look pretty nasty after awhile. They pretty much just shrivel up due to heat.
 
Can't find leak...

Can't find leak...

OK. I was spraying every hose I could find, checked the accordian hoses etc. I can hear a "hissing" sound but I can't seem to find it.

If I am standing in front of the car, it is coming just to the left side (passenger side) of the engine. Right around (key word being "around", I can't really pinpoint it) where the belt is (not a belt sound).

I jacked up the car, and saw a few hoses in the front passenger side as well, but they seem fine too, and the hissing sound seemed to be more "distant" sounding when I was under the car.

What could it be that I am not seeing?
 
I sprayed the bajeebers out of them (at least as best as I could). The manifolds themselves make it somewhat difficult to spray all the way around each gasket.
 
Yes, as posted earlier, spray carb cleaner at UIM/LIM gaskets and check for "hiss" near the exhaust manifolds too. The last "hiss" sound I got, it was a broken O2 sensor tip for me. But I got CEL codes for the O2 sensor so that helped me diagnose it. ;)

Edit. If you have both Bank 1 and Bank 2 leak codes (P0171 and P0174), you should check for leaks at the accordian tube or near there or vacuum hoses again. It is less likely to have two gasket leaks or two exhaust leaks (one at each bank).
 
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What if the engine is cold from sitting a while? I am sure that it would heat up quickly, but would that be better just to make sure?

Also, is there a picture somewhere showing all of the vacuum hoses? I just feel like I am missing something obvious...
 
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