Do fuel tank screw-caps go bad? o_O

[LancerZero]

This probably isn't a big deal, but it's something that's happened to me twice now and I was curious if anyone else had experienced any similar problems. I already searched the forum a few times, and came up with nothing; but I dunno.

Here's how it goes: with no apparent cause, I'll be driving along and the check engine light will come on. No change in how the car runs or sounds, nothing. I'll stop at AutoZone, and the code read will say "EGR insufficient flow". Last time this happened, I was advised to try replacing the fuel tank cap-thing. Sadly, I don't know a better name for it, but it's the scew-on lid. I replaced it, they cleared the code, and it stayed gone for about three thousand miles over the course of about two months.

This morning, it came back again. I changed the fuel cap and had 'em clear the code again, and the light went away and hasn't come back. Of course, I've only driven about four miles since then. We'll have to see what happens after my forty-mile drive home from work.

Now, of note is the fact that the first time this happened, I noticed that the fuel cap was the same as the AutoZone one. The EXACT same; it had been replaced at least once before. There was nothing visibly wrong with it, but replacing it seemed to fix the problem, so I tossed the old one. Same thing here. Nothing apparently wrong with the old one, but replacing it seemed to do the trick.

But I'm concerned, because I just got the timing belt, serpentine belt, and power steering belt changed two days ago. After that, I can't afford anything more expensive than a fuel cap for awhile . . . is this a recurring symptom of a more serious, deeper problem? Or is it likely just a silly little quirk that'll have me spending $6 every few months, a little annoying but nothing to worry about?

Also, though, I haven't been experiencing any of the problems that I've heard associated with a problematic EGR system. My mileage is good and consistent at about 27mpg; there are no surges, no hesitation, no rough idling; no smoke coming out of the tailpipe . . . if it's just a little quirk, I can totally live with it, because I love my Camry. It's an excellent, solid, reliable car. But I don't want to risk having to pay for major repairs later on because I just swept this under the rug.

[Mike Gerber]

The "gas caps" generally don't go bad. On an OEM Toyota one you could just replace the o-ring that makes the seal. Not sure about the aftermarket ones. You probably do have a problem with the EGR system. They can become clogged with carbon. If the code returns, I would remove the EGR valve and the tube attached to it and clean the carbon out of both. Do a search for "EGR cleaning" on this forum. I would try this first and see if the check engine light stays off. The EGR valves themselves can be a bit pricey.

Mike

[LancerZero]

I know it's been awhile, but I've only just now been able to replace the EGR VSV valve and confirm that it fixed the problem. Thanks for all the help, guys!

[xfeejayx]

thank you for reporting back