2012 Scion XB with 250000 miles, engine is still strong, first prob I had was smelling gas fumes, my mechanic said needed new fuel pump...then 3 days while filling up tank ..gas started overflowing under my car...my mechanic replaced fuel pump again...then, about 2 weeks latter my chk eng. Light came on, had first mechanics say it was Pvc and hose..changed it...chk eng light came back on...then changed air mass fuel sensor...chk eng light came back on...then said it was my charcoal canister, so went and replaced it with a auto zone brand...chk eng light still on..replaced one other part as well. ....Some weeks the engine runs wonderfully no idle problems then out of nowhere it starts idling really funky at stoplights and stop signs and I have to put it into park to keep it from dying ...otherwise it still runs great ..what could be possibly causing the check engine light to be on? Had another mechanic look at it said it was still my charcoal canister and that that canister made by AutoZone was worthless the problem is why would it work some weeks and then engine light will go off and then come back on and start idling rough again it's like there's some sort of valve in there getting stuck and then getting stuck open I don't get it and nobody no tech has been able to find out what it is..need to get emissions test done soon help
Can you list the exact code number(s)?
1. Ask around for a known reputed mechanic in your area.
2. Take the car to your nearest auto parts store, scan the codes & post them here.
3. In future, avoid throwing parts at a problem without doing a thorough diagnosis of the problem.
I can’t imagine how many thousands of $$$ you’ve thrown at your car, and the problem still not being fixed.
Started out with a mechanic friend who worked at brake Masters which I finally got fed up going there because they kept pushing more and more parts at me. Then went and spent money on a really good mechanic had all the tests done they came back and said the canister is bad because it's a canister from autozone? I guess the brand of canister it's supposedly not a good canister and could be the problem the problem is the canister they want me to put on is an $800 canister the canister I did put on through AutoZone was almost $300 less do I really have to put on a new canister and can I get my money back from the AutoZone canister if that is the problem? LOL whole thing is just crazy didn't realize how a leak in the system could cause so much problems I still feel like there is something not opening or shutting properly somewhere just not sure where to look for that because I'm not a mechanic it's just a gut feeling
Are they sure that it’s a bad canister? And is the $800 canister, OEM? Call up Autozone & ask them if they accept returns.
If you're in Tennessee, I'd go see Scotty. If you're in upstate NY, you'd go see Eric O. at South Main Auto. If you're near Penn State, Ivan at Pine Hollow Diagnostics would be "the man." If you're in Baton Rouge, Louisiana, you'd go to AgcoAuto. What's common to all of these folks: They are "A" level diagnosticians, rather than folks who indiscriminately light what Ivan calls "the parts cannon." You know how much that costs, and how aggravating that is.
The check engine light is just the last indicator. A decent scan tool would have enhanced diagnostics/Mode6 and live data. And stalling at idle can be caused by any number of things, dozens, in fact. That's why you need a first-class diagnostician, and not someone who just throws parts at things:
For example: Idling problems can be a dirty MAF sensor (or, perhaps any aftermarket, non-OEM sensor). Did you replace the MAF with an OEM sensor, or a Chinesium one from the parts store? If it's the latter, it's better to get a used OEM salvage sensor, for $20, as I did for my 2008 Camry.
If the throttle body is clean, perhaps there's an issue with the throttle position sensor.
Or, alternatively, if the fuel pump was replaced, IF it was replaced with a Chinesium aftermarket pump, that might not be good. New is not the same as known good. Again, a used OEM part from a salvage yard would be better than a non-OEM Chinesium part (and much cheaper, BTW).
Or the fuel pump and filter could be good but the fuel line is clogged. That's another possibility.
And the PCV: Again, OEM (which is cheap, new, BTW) will work properly. The Chinesium parts store one? A crap shoot, at best.
As for a "stuck valve," that would show up on a scan tool, such as a Blue Driver. That might just be some carbon buildup.
I don't know. These are just some possibilities, not all of them, by any stretch of the imagination.
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Additionally, all these problems may NOT be related. It's an old vehicle, after all.
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If I were you, I'd work hard to find a true diagnostician, someone who would guarantee that the problem would be fixed, and would back up that guarantee (12 months?)
I'd also ask for a general inspection, FIRST, with the idea that you'd need an assessment of any other actual or potential problems before you'd make a decision about repairs. Every car comes to a point of NEFR (Not Economically Feasible to Repair). It's a cost/benefit equation that requires some real data.
Good luck.
What are the codes? Anytime you get a check engine light, it is usually associated with some codes.
Next time the check engine light comes on, read the codes with a scan tool.
If you go to AutoZone or an auto parts store, they usually let you borrow them for free or even scan your codes for free. (Unless you live in a big city like me, and they always seem out of them.)
The codes will give us a clue.
Those codes can help point us to the right direction of what your problem might be.
The codes are saying that it's coming from a leak in the system, smoke test was done first time showed that it was canister. After fixing the canister it's still showing a leak did another smoke test there was no leaks to be seen. Also I did change the gas cap like I said many many parts later still can't figure it out
What’s the code number?