Check Engine Light Code

http://Toyota.autoboardz.com/Check-Engine-Light-code-2002-Dodge-Ram-7L-V8-ftopict217775.html (Check Engine Light code 2002 Dodge Ram 4.7L V
Hello - I have a 2002 Dodge Ram 4.7L V8 I did the on off on off on trick with the key in the ignition and got two codes for my check engine light P0442 P1491 The first one is in my Haynes Manual - EVAP system leak monitor, medium (0.40) leak detected Question #1 - what does that mean? I was told ..
« Could be a loose gas cap. If it's something else, it should be covered by the emmissions warranty. According to my ODB2 Reader documentation, for Chrysler, that's "Radiator fan relay control circ.. »
« I know how to replace a fuse; what's involved in changing a relay? »
« The same as replacing a fuse, just pull it out and plug the new one in. -- If at first you don't succeed, you're not cut out for skydiving "Radiator »

http://Toyota.autoboardz.com/Explorer-Catalytic-Converter-replacement-ftopict223064.html (Explorer Catalytic Converter replacement)
Had my Explorer in for service at the Ford dealer, and because of a check engine light code, they said I needed to get my catalytic converter replaced, as well as the rear O2 sensors (it's a much longer story than this, but...this gets the point across). The dealership then said I also needed to g..
« My limited experience with after market cats leaves me with the feeling that these are cheaper for a reason.... There arer many horror stories where an owner has chosen the less expensive route on.. »
« 1998, 4.0 SOHC. Part of the "long" story is I originally had universal cat placed in, and just replaced with OEM direct fit at a muffler shop. »
« Sounds odd that a muffler shop can "do" OEM cats cheaper than the dealer... I searched TSBs for 98 EX and FSAs.... no indication of a later calibration (reflash). Unfortunately, the best way to be .. »
« It also requires some equipment that costs thousands dollars as well as the ongoing costs of training the techs to use that equipment mike »

http://Toyota.autoboardz.com/99-grand-Check-engine-light-code-p1652-ftopict224837.html (Okay 99 grand am Check engine light code p1652)
I was able to solve and fix the other codes but dont know what this code means p1652. Tried internet search think its one of these but not sure. This is the only one i have left so i could register the car and turn off the check engine light.. P1652 Idle Air Control Valve Control Circuit P1652 Po..
« According to my (Auterra) scanner, the code P1652 for a GM vehicle is "Cooling Fan 2 Relay Control Circuit"... which makes sense because you already said you messed with the wiring for the second .. »
« Well i'm taking it to my mechanic to check it out. Thanks for the info. Looks like Gm did a update for there OBD II codes So it could be powertrain induced chassis output circuit or Cooling fan rela.. »
« That "Powertrain Induced Chassis Pitch Output Circuit" sounds like it's part of an "Electronic Suspension Control" system that your car probably doesn't have: »

http://Toyota.autoboardz.com/2001-Grand-evaporator-emissions-leak-ftopict249156.html (2001 Grand evaporator emissions leak)
Check engine light code says I have a small evaporator leak. can't pass emissions. Replaced cracked evap canister hoses. Ideas?