Can a loose oil dipstick cause a check engine light

AMANDA CHURCH

MEMBER
2005 VOLVO S40
2.4L
5 CYL
2WD
AUTOMATIC
163,000 MILES

I have the car listed above (second gen). I have no idea what's going on so I'll give you a backstory.

Back in April my car had several problems at once - battery, coolant leak, and supposed dying fuel pump (ECM-261A). I had these all replaced and everything worked fine. Six weeks later my car hesitated, died (exactly the way it did with the fuel pump - in video) and wouldn't start whatsoever - but no code. After an hour of sitting, it started fine and has been working ever since. This problem seems to be random and comes without warning, which is not good for out of town driving.

Today, it threw a p0171 - lean condition in bank 1. I apparently didn't push the oil dipstick in all the way after checking it. Could this code be caused of a loose dipstick or possibly related to a fuel pump issue?

I plan on taking it to a garage asap, but would like to have more insight on this code.

Thanks!

2 Replies

KASEKENNY

MECHANIC
18,907 POSTS

So, this code is telling us that we have a lean condition, so we need to just make sure we run through this info to be sure we don't have another issue.

https://www.2carpros.com/articles/repair-lean-mixture-codes-p0171-or-p0174-on-some-manufacturers

However, yes. On these Euro cars a dipstick that is not secure can cause a vacuum leak and it will set a check engine light so the other way to go on this is to secure it and then clear the code and see if it returns.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

If it does not, then that was the issue.

Please run through this and let us know what you find and if you have other questions.

Thanks