Check Engine Light but No Codes

[shrimpyshrompy]

Hello! I'm new to this forum and not great with cars, so please bare with me lol.

Recently, my 2004 subaru baja has been having issues with the check engine light coming on, but no codes coming up. The past couple times I've taken it in to AutoZone, it's come back with nothing.

The first time it happened I ended up taking my car in to get the fuel pump replaced since it was about time to anyways, and that seemed to fix the issue for about a week. But now, it's back on again, and I'm at a loss for what it could be. I've checked all the basic things (gas cap, etc.), but none of that seemed to help.

I will say, because of the age, my car does have a lot of issues lol. It's my first car, and the person who owned it before me didn't do a great job of take great care of it, unfortunately.

I'm likely going to take it in to the mechanic just to be safe, but I would love any second opinions or thoughts, as I'm at a loss.
Thanks all :]

[20Baja06]

Turbo or non-turbo?

Can you provide more information, like under what conditions, the CEL comes on? Cruising? Heavy acceleration? Etc.

[anarchy1024]

Did you reset the CEL using the scan tool? How soon after you reset it does the light come back?

A Baja as your first car? That's a bold call... I love mine, and never plan to sell it, but I'd never recommend one as someone's first car (that is, unless they plan to do at least some of the work themselves, have a bit of excess spending money, and access to a backup car to use when the Baja needs work).

[shrimpyshrompy]

Turbo or non-turbo?

Can you provide more information, like under what conditions, the CEL comes on? Cruising? Heavy acceleration? Etc.

It's non-turbo with 170,000 miles!

From what I've noticed, it's come on while I'm accelerating (usually when I'm getting on the interstate/highway). It's been happening on and off for about a month now, it'll come on while I'm accelerating, stay on for a day or two, and then randomly I'll turn back on my car and it'll be off. It's about the third time it's happened now. There's no pattern I've noticed for when the CEL will turn off, sometimes it'll be after the car sits for a day, sometimes an hour.

[20Baja06]

Not that I’m an expert, by any means, but my first thought was knock sensor. Under heavy acceleration could support that, but it is a complete shot in the dark without further diagnoses.

[Twempie]

FWIW

I'm the original owner of a 2006. I live in Seattle and when going east/west over the Cascade Mountains, the check engine light will come on then go off on its own accord a day or two later. The car is regularly maintained and in relatively good shape.

I had the same check engine light issue when traveling to Chicago last year - the light went on and off after long days of several hundred miles. The car has about 105k miles on the odometer and, as best as I can remember, the check engine light has been going on-off since my 2006 purchase. I stopped worrying about it several years ago.

YMMV.