2001 Windstar and P0155 and P1151 Codes

[dshea19]

Allright, here we go. I used to have the common P0174 codes and such. Replaced the valve cover and upper intake seals and bolts. Also, had to replace my IMRC. It has a new idle air control as well.

After all of that, I am popping these codes: P0155 and P1151. I am fairly sure I have zero leaks anywhere. The rear vacuum line has been replaced along with the pcv line that came with the intake plenum kit. When I first start the van, it wants to idle high and race a little. After about a minute of driving, the high idle and racing go away and I get an occasional dip in rpms every so often.

So, any ideas?

[olopezm]

Those two point to the Bank 2 Sensor 1, which is upstream (pre-cat) sensor at the front of the engine compartment. Before you replace them, make sure the wiring is intact and the connections are clean.

P0155 - 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1). It IS NOT related to engine malfunction, but to the sensor itself. These sensors have a heater circuit to bring them faster to optimal operating temperature.

P1151 - Lack of HO2S-21 Switch, Sensor Indicates Lean. This one DOES relates to engine performance. If Wiring is intact, make sure there are no vacuum leaks at the front valve cover and the PCV is correctly installed. Since the valve cover was replaced, did you properly tightened each one of the bolts?.

Oscar.

[dshea19]

Thanks.

I have checked the bolts for the valve cover. Tight as can be. The clip for the o2 sensor was broken, but the connection seemed very snug. I made extra sure it was tight and then wrapped some electrical tape around it to make sure it stayed that way. I also did another check on the vacuum lines and such. Everything is cool. If this doesn't clear it, I will replace the pcv valve and the o2 sensor. If that doesn't fix it, I think I will just set it on fire and call it a day.

[dshea19]

Code came back. Looks like pcv and o2 change is next.

[wiswind]

I recommend a Genuine Motorcraft PCV valve.
Many aftermarket brands do not properly meter the flow.
It is more than just a check valve.....it controls the flow under varying vaccum conditions.
The valve pushes against a spring.....making the opening smaller for high vaccum (like when your engine is a idle) and larger when the vaccum is lower (like when you accellerate).

Rockauto sells the genuine Motorcraft brand Oxygen sensor.
Getting Motorcraft will get you a sensor that will be better matched to the switching charactoristics of the FORD specifications.......and the sensor in the other bank.
This sensor is used to control air / fuel mixture......a direct impact on fuel economy and how well your engine runs.
Also.....it is better to get one that has the correct plug on it......"direct fit".....
The codes for the heater are looking like a Oxygen sensor issue.......since you have verified the wiring......that leaves the PCM (computer) if it is not the sensor.....and that is a LOT more money......and also much less likely to be the issue.

[dshea19]

Well, I replaced the pcv valve and the o2 sensor. Didn't get the advice about Motor Craft until I had already bought the parts. The plug for the o2 was a direct fit. No gymnastics to make it work. Just install and pung in.

Anyway, still have codes. I think it is time to find some matches and have a bonfire.

[tempfixit]

Originally Posted by dshea19

Well, I replaced the pcv valve and the o2 sensor. Didn't get the advice about Motor Craft until I had already bought the parts. The plug for the o2 was a direct fit. No gymnastics to make it work. Just install and pung in.

Anyway, still have codes. I think it is time to find some matches and have a bonfire.

Do a smoke test to double check for vacuum leak.

Video of poor mans ways:

http://www.youtube.com/watch?v=zMok2...2&feature=plcp

Did you clear codes and drive?

[wiswind]

To add to what tempfix mentions....the code(s) and light will stay on for a given period of time AFTER the problem goes away.
You need to clear the code(s) which will make the light go out.
THEN....see if the light comes back.......if it does....read the code(s) again to verify what code(s) you have this time.

[dshea19]

Originally Posted by wiswind

To add to what tempfix mentions....the code(s) and light will stay on for a given period of time AFTER the problem goes away.
You need to clear the code(s) which will make the light go out.
THEN....see if the light comes back.......if it does....read the code(s) again to verify what code(s) you have this time.

Correct! Just found that out. The codes are gone. I tried to get it inspected today, but I got the "not-ready rejection." So, I have some driving to do before I can get it ready to inspect. I wish there was a faster way to make that happen.

Thanks for all of the help guys. I really appreciate it. I can do repairs all day long, but troubleshooting is beyond my wisdom. You guys are great!

[wiswind]

No way around the "drive cycle" part of it.
From what I've read, the last test (longest to complete) is the catalyst efficiency test.
Short of some very creative computer programing which is far beyond me, driving the vehicle is the best way to complet the test.
Maybe include a drive or so that is 30 minutes or more in length.......if you drive 5min each way to and from work.....it could take forever to complete.