Not an esy code for a DYI guy to chase .

It is as the generic description states of a large system leak.
So it is unable to reach the target pressure to test the system.

It being a 420 car it uses a Chrysler LDP type evaportive leak detection system.
Google LDP evap operation
Anything not allowing LDP to pump up at all or pump enough due to leak and close reed switch will cause this code 420 car only.

So look for lines having cracks or damage and make sure LDP has it's vacuum source.
Otherwise these problems have to be diagnosed with all the proper tools.

Awesome, thank you! This was something I didnt know. Gotta love Chrysler .

Update on this, hopefully this bumps the thread for some fresh ideas and input on this situation as it really bothers me. This being my DD...

So this large evap leak... what could it be. I've done so much research on this even the LDP research helped but couldn't quite get me there. I've been inspecting my EVAP lines to see any evidence of SOMETHING I mean anything come on car give me a hint! Pulled my seats out to check the tank, got a new gas cap. I mean really like sniffing around like a dog for these stupid hydrocarbons. Ended up feeling the lines for cracks coming from my purge valve solenoid, take a look at my finger... what do ya know, black soot all over the place. Idk where specifically these HC are leaking from but I believe it's in the line set somewhere. I'll do further inspections later. If anyone is having issues with EVAP now or in the future, these HC are dirty and will coat whatever they touch. Just check where your gas cap is, if you haven't cleaned it or it hasn't been cleaned ever, dirty huh? Our cars have a special cap that allows venting but can allow for vaccum to be pulled (at least that's what I've read).

EVAP leaks suck... I've heard the small ones are much worse though.

I've still got a small leak somewhere too. I want to just delete the whole system since I don't have to pass emissions, but I'd hate to have that check engine light on all the time.

I watched a video a while back that stated the causes of evap codes, and it said that one of the causes could be a leaking filler neck. Let's hope that's not the cause but it's just an idea.

Do you think maybe you have a bad evap purge solenoid? I have a used one in my garage, but it works and throws no codes if you need it.

By the way, if you had a bad ldp you would get the code p1494.

I got a purge solenoid from doorman, coincidentally it was the same one just without the rubber grommet to fit on that piece of metal. Tried it out and code was thrown. I've check my original one and it appears to be in working order. Cant blow through it. I wouldn't entirely rule out the filler neck. Mine is quite rusty and salt coated as are most things on my car unfortunately... but as for smooth surfaces around areas of your evap lines it you see black soot just know those are hydrocarbons and they love to stick to anything, it's easier to tell on a smooth surface like metal with paint

Does you cruise control work?

BLACK'98DSM said:

Does you cruise control work?

Click to expand...

Yes it does. And forgot to mention I live in NJ and they check for evap for years 96 and up? I think, or its 95 and up I forget. Prior to that they don't check emissions so just my luck haha. I would delete that system if I could, I've read a few ways to where it wont throw a code. You have to make sure that pump can pull vacuum basically

Yea I'm guessing you just have a pinhole in one of the lines. As long as you're not throwing ldp code and all your lines are properly routed that seems to be the only thing that could go wrong.