QuestionQUESTION: Hello. I have a 98 corolla. My fiance and I bought it with the check engine light on about 2 months ago. I have been trying on my own to troubleshoot the issue myself, but alas I am at an endpass and am about to take it to a mechanic. I do not hate mechanics, I just prefer to be able to fix an issue myself and save the expense. Anyway, an auto parts store read the codes for me and gave me 2 codes: P0441 and P0446. They asked me if I ran the car without the gas cap on and I would never, but I cant be positive of the previous owner. I attempted, well did clean the trottle body and the idles air control valve, plus looked into other air flow issues that may be causing a bigger problem. If you could tell me what the codes mean, I am positive it will fix other problems I am having with the idling. But thats another question hopefully for another day. Thank you for your time and reading my rambling. Pat
ANSWER: Hello, those codes indicate a leak in the fuel vapor recovery system also called the evap system, lots of times they can come up because of a leaking gas cap and also a bad evap purge valve, first I would replace the gas cap with a OEM part from the dealer, check the fuel filler neck for damage, clear the codes and drive it a few days, see if the light comes back on and note how long it took to do so.
What kind of issues are you having with the idle?
Does the engine have normal performance otherwise?
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QUESTION: Normal while accelerating. Jumpy and sounds like its choking while in gear at a light or sign. Only while its at temp. Before the motor warms up, it is normal functioning except idles high in a steady increase. Starts at 1100-1200 rpm then climbs to 1600-1800. Then it drops to 800 and then wants to start play games with me. I thought it was the idle air control valve, so I took out the throttle body and cleaned it all. It was a mess. Checked all the sensors and hoses for cracks or leaks. Didn't see any issues there. My next step is to add some injector cleaner, check pcv valve, and see if the exhaust pipes are lined up properly from the intake manifold and at the exhaust manifold. I'm going through a list of issues others have had that they shared online. Which is how I got to this site. Again, thank you for your time and knowledge. Side note, the check engine light went off on my way home from work today. As I got an alert that I had an email saying my answer was ready.
AnswerThanks for the update, it sounds like there is an intake leak, I would recommend checking intake manifold vacuum, also locate the vacuum hose coming from the intake going to the purge vsv, it is mounted on or near the air filter, you'll see a green cap on one of the hoses, this hose goes back to the tank, the other hose comes from the intake manifold and has steady vacuum, pinch this hose or block it and see if the idle goes to normal, if it does the vsv is leaking, staying open, which can cause the erratic idle.
