code p0171 lean bank 1 after clutch master cyl rep

[hardcore302]

I got my clutch master cylinder replaced at the dealer. When I started it it threw code p0171 lean bank 1. The car was fine before. They told me to come back monday and I almost killed him. Is there something during the clutch master cylinder replacement that they could have screwed up to throw this code? I dont know what other things must be removed in the process.. intake vacuum or exhaust leak? I saw the list of things that cohld throw the code but some of them dont make sense in this situation. It cant be a coincidence. Car is 2007 mustang gt stock intake. Thanks.

 

[Trav]

Check for a vacuum hose off.

 

[GSCJR]

This ^^^

 

[hardcore302]

Thanks. Im not too good with thst stuff but ill poke around

 

[hardcore302]

Which side is bank 1 on my car? Would that be the side where the hose is off? Its just lean on bank 1

 

[hardcore302]

bump please

 

[bdcardinal]

Bank 1 is the passengers side.

 

[hardcore302]

It's been almost 500 miles and the check engine light never came back. Is it possible he turned the car on during the repair to see if the clutch was working and then triggered the light? Then reassembled everything and didn't clear it? Thanks!

 

[hardcore302]

bump please

 

[01rangerxl]

Yes, that's very possible.

If the light is not on, I wouldn't worry. If the problem that turned the light on was still present, you would see the light, even if only intermittently. The computer is not just going to say "ok, I can live with that" and shut it off.

Vacuum leaks can set a check engine light very quickly...almost instantly if it's a big enough leak. Ford also uses lots of small vacuum lines everywhere, so it's easy to disconnect one or knock it loose. Odds are at least one vacuum line had to be disconnected or was close enough to get knocked around during the repair. Unless the plastic tube itself broke, usually fixing it is as simple as plugging the connection back together.

Usually finding vac leaks post repair is easy enough...follow every piece of plastic tubing in the area that was being worked on.

Ford's PCV plumbing can also cause lean codes on a variety of models and engines, but given that this happened immediately after a repair, the vacuum lines would be more suspect unless some PCV hose or connection might have been bumped or disconnected.

 

[bdcardinal]

There aren't many vacuum lines on the 3V motor, there is no EGR on this engine. Either check the PCV hose on the passengers side, they have a quick disconnect type fitting on either side. Also check the vacuum line to the brake booster as that is near your clutch line.