Evaporative Controls Check Engine Light that Dealer CAN'T FIX!

[danl]

My sister bought a 2001 Toyota Corolla S brand new in the summer of 2002. In the summer of 2003 it threw a CEL for the Evaporative Emissions Sensor. That is the sensor that determines that there is an air leak in the fuel system causing the pressure in the fuel tank to drop which means there is a leak and gas fumes are released to the atmosphere. This only happens on hot days. It’s been in the garage numerous times since then and has never been fixed. They have replaced check valves, which haven’t solved the problem. I am suspecting bad mechanics and poor diagnosing.



Does anybody know of, or how to find possible TSB or recalls for this car? Is this a “common” problem that enthusiast have narrowed down to a part that needs modified or replaced. I have no clue, or I’d fix it myself.


EDIT: Sorry I posted this in the wrong forum. Needs to be one down if a moderater could help me out.

[manasseh61]

hi Danl, my advise is back to the dealer , let them re diagnose to use smoke machine to detect the leaks on the evap system,

[ALL TRAC 88]

what code id it throwing p0441 p0446 ??? theres usally 5 problem areas
1. gas cap not tightened
2. VSV on charcoal can is bad
3 VSV on aribox is bad
4. CCV on air box is not good
5. Charcoal canister is leaking

[ShawnM]

I would take it back to the same dealership, but talk to the owner or a manager about all the problems you have had. If you go somewhere else they will start the whole process over again. At least this dealer already knows what they have replaced. Evap. system codes can be tricky but any tech. that knows what hes doing should be able to track down the problem. As manas said, ask them if they smoke tested it. The smallest pin hole in the system will cause the check engine light to come on. Im not saying that is what your problem is but we had a 99 camry come in last month that had a very small leak in the charcole canister. Theres no way we would have found that without the smoke machine. I would leave the car with them and insist on a loaner car since they havent been able to take care of the problem.

[brockyjr]

hello ,
On a 01 corolla, checkto see that you have a vacuum in the gas tank.(let tank get down to !/4 full open gas cap you should hear the air sucking in) if not your cap may not be tight or may need replacing (full serve guys almost never tighten a gas cap right) it should click 5-8 times. disconnect your battery to reset the cpu after your next fill with the cap on tight before you take it back to the dealer. hope this helps