Contour Enthusiasts Group Archives Forums General Troubleshooting Very low power and stalling.

Hi all. I'm dealing with a problem on my 99 SVT that I could use some help with.

So I bought the car used with 71,000 on it. It now has about 73,500 on it. I got a used car warranty from the dealer just in case anything went wrong. To make a long story short I've put in over $5000 in parts and labor on items that were not covered by the warranty; gaskets, shift cables, axles, replacing aftermarket parts, etc. Now I'm at a point when I just want to get rid of the thing. However, it's not running right and I don't know what to do.

The car was in the shop about a month ago and they did a bunch of work including a tune-up. When I picked it up everything was all good. Although, one in every five times I would drive it, the secondaries wouldn't open up after 4000 RPM. Not too big of a deal and I though since it had not been driven much, maybe they would smooth out. They did start acting right after a couple of weeks. Then we had a ton of rain and the check engine light came on. I though maybe something got wet. Rather than pay the $150 diagnosis fee, I bought a code reader of eBay for $50. I read the codes, looked them up and reset it. I figured the rain probably caused them and if they were real, they would appear again. I don't have them in front of me but they related to O2 sensors and a lean condition. That was about 2 weeks ago.

Lately the car has been running pretty good. However, it is burning a quart of oil every 250 miles (one tank of gas). Makes me a little nervous, but the engine should be covered if it needs a rebuild. I checked my parking spots and it doesn't seem to be leaking. When I first start the car a whitish smoke exhausts. Also, sometimes it smells like burning oil coming out of the heater vents.

So I�m driving home from work on Friday and I notice the check engine light came back on and it�s a bit sluggish. When I step on the gas I don�t get a really strong pull like normal. However, I can still feel the secondaries open up. So as I�m nearing my house, every time I stop, it stalls. When I attempt to start it, it doesn�t just start right up. I have to crank the engine for a minute. Almost like a fuel problem. The shop is a couple blocks from my house so I drive it over there. The guy takes a look and sees that the PCV valve has come out of the tube. There's an oily smelling smoke coming out of the tube where it connects. It looks like it�s been disconnected for a while. It�s not completely out of whack so I think it�s been functioning off and on. So I take the car home and clamp it down Saturday morning. I drive it on short trips all day Saturday and Sunday without a problem. The oil smell is gone. The car is still just a bit sluggish.

Monday after work I read the codes, P0171 and P0156, and reset them. I wanted to wait just in case I needed to take it to the shop. On the way home after resetting the codes, it�s really doggy and starts stalling every time I stop.

I don�t know what the hell to do. I think it�s either a fuel pump, fuel filter, IMRC, or the PCV valve. Also, it probably needs an engine rebuild because of the oil consumption. However, I�m thinking that maybe the oil was leaking/burning off the PCV leak. I don�t really know how that setup works. If I take it to the shop, they�re going to charge me $150 to diagnose it. I can replace the IMRC and the PCV for that. If it is the IMRC, it�s probably not covered under the warranty and I�ll have just wasted the $150 diagnosis fee. So what do you guys think? Do you have any suggestions? I can replace most parts myself as long as they don't require special tools. Thanks!

You should test for headgasket leak, check for vacuum leaks in the engine bay (is there a hissing sound?), clean the MAF and check/change the Bank 2 lower O2 sensor, and go from there. You can worry about the IMRC later. And do you have an exhaust leak?

Edit.
The el cheapo headgasket test.

Fill antifreeze to the brim on recovery tank (leave cap off). Remove all spark plug wires. Remove all but one spark plug and have someone crank the engine. If the antifreeze bubbles over, there is leak from that portion of the engine (or cylinder). If not, go to the next cylinder, and then the next.... Note, it could be more than one area or more than one cylinder. Good luck.

From TSB,

P0171 - System Too Lean (Bank 1) The Adaptive Fuel Strategy continuously monitors fuel delivery hardware. The code is set when the adaptive fuel tables reach a rich calibrated limit.

Fuel System:
�· Contaminated fuel injectors
�· Low fuel pressure or running out of fuel (fuel pump, filter, fuel supply line restrictions)
�· Vapor recovery system (VMV)

Induction System:
�· MAF contamination
�· Air leaks between the MAF and throttle body
�· Vacuum leaks
�· PCV system concern
�· Improperly seated engine oil dipstick

EGR System:
�· Leaking gasket
�· Stuck EGR valve
�· Leaking diaphragm or EVR

Base Engine:
�· Exhaust leaks before or near the HO2S
�· Secondary air concern

Powertrain Control System:
�· PCM concern

MAF sensor

http://www.contour.org/mods/mods.php?s=howto&displayid=36
and
http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=zetecmaint&Number=989728&page=&view=&sb=5&o=&fpart=1&vc=1
and
http://www.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/1b/cb/25/0900823d801bcb25.jsp

From TSB,
P0156 - HO2S Sensor Circuit Malfunction (HO2S-22). The Bank 2 (radiator side) downstream HO2S sensor(s) are continuously checked for maximum and minimum voltages. The code will set when the voltages fail to meet the calibrated limits.

�· Disconnected sensor
�· Pinched, shorted, corroded wiring or pins
�· Crossed sensor wires
�· Exhaust leaks
�· Contaminated or damaged sensor
�· Chafed/damaged wiring

Bank 2 Lower O2 sensor;

On this 2-Dimensional picture, ignore the red box and arrow, the Bank 2 Lower is the sensor on the right of the pre-cat. The arrow is pointing to the Bank 2 pre-cat

Originally posted by chongo:

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Tony, thanks for all the detailed info! I really appreciate your time to put that together. I'll order the O2 sensor today and clean the MAF sensor tonight.

I haven't noticed either an exhaust or vacuum leak. When I first got the car there was a vacuum leak that was causing the heater to stick in the defrost position. The ford dealer replaced a bunch of lines and it has been great ever since.

The head gasket may be another story. I�ll have to check that out. Would the head gasket cause the oil consumption? If not, what points you to the head gasket? Is it the white smoke on a cold start?

Also, I found the codes from my first read. They are P0174, P0420, P0171, and P0156.

Thanks again. If anyone else has any more input, I�d love to hear it.