Car running BAD, EVAP codes... WTF?!

[propain]

This has been an ongoing problem for awhile... it's gotten 'better' in the fact that the car doesn't stall as much anymore, but it still runs like crap.

The History:Awhile ago, my car would just randomly stall, didn't matter if it was idling or driving... Since then, i have replaced:Cap/RotorPlugs/WiresFuel Filterand most recentlyMAFS (not an expense i'm happy about incuring since it didn't fix the problem).

I'm still getting the same set of diagnotic codes thrown, always in the same order:Knock Sensor followed by 2 EVAP codes (dont remember exactly which ones off the top of my head).

Basically, i'm just sick of this, and want to know if anyone has any ideas of what might be going on... We disconnected the vaccum from the evap system and presurized it (to force it to turn on) and the car stalled. - My understanding of the purpose of that system, is simply to suck gas fumes from the tank and burn them so they dont blow off into the air when you open the tank to fill up.... i dont understand why the car would run like sh** when the evap presurizes.

Any suggestions/past experience with this?

TIA

[p00t]

sounds strange, have u checked all hoses for leaks?

im too much of a n00b to help, but could a knock sensor be going off due to a very lean condition, somehow getting way too much air? may be possible the knock sensor is faulty and its really screwin up everything when it triggers?

how often is "randomly stalling"? once a day... a week... every 10 min?

[propain]

how often is "randomly stalling"? once a day... a week... every 10 min?

Totally random... sometimes i go for a week, sometimes it's a couple hours. Each time, when it dies, it's just like you turned the key off... No sputtering etc... just off. - After it sits for a sec, it will come back on and run again for some 'random' amount of time.

Your theory about the 'too lean' condition is correct, in all cases, when the car stalls, the mixture is so lean that my split second AF meter can't even pick it up (all lights off), this is the same thing that happens when we presurize the evap system.

It's really starting to mess with my head. *crosses fingers and hopes it's not the ECU*