Hello Everyone,

I recently purchased a new to me 2003 Dodge Ram that only has 57K miles and looked really well taken care of. I got the check engine light a few days ago and the code was P0442, so I got a new gas cap and replaced the old one. Today, the light came back on with a code of P0456. What would be the next step to check? I hope it is an easy thing to fix. I thought I made a good purchase on an older truck, and don't want to regret that decision.

Thank you.

 

Very common, especially when a Ram gets a few years on it. A search of this section will show a lot of results.

It's an evap leak, and as said many times over, the hoses used by Dodge are not the best quality and the hose clamps are the cheesiest I've ever seen.

Trace the evap system, looking for a split hose (usually a hose end) or a broken hose clamp. Hose is cheap at about a buck a foot and the good quality type hose clamps, the kind you close with a small socket or screwdriver are under a buck a piece.

Use the Evap system map I have in the FAQ section to trace the lines. I'd start right at the canister if it was me.

https://dodgeforum.com/forum/3rd-gen...m-diagram.html

If this is the worst thing wrong with your 8+ year old truck, you've done well...

 

Thank you so much Hammer,

I actually just took it to the dealership since they tried fixing the problem the first time around by replacing the gas cap. They have agreed to look it over and fix what they can free of charge. If I get it back and the light comes back on then I will replace the hoses and clamps as you suggested.

Thanks for the help.

 

Welcome to the site BTW. Please report back with the resolution

 

The first fix is always the gas cap. My ex wife could never get used to tightening the thing on till the first click. She was always afraid that "click" meant she was breaking something. Was many a time I fixed an evap CEL on our Grand Cherokee by going out and twisting the cap a quarter turn...

 

Just got a call from the dealer, they had the truck for over a day now and all they did was replace the gas cap AGAIN! I told them it was already done, but they said that this time it was replaced with a Dodge factory cap so it will keep the pressure better. I told them to hang on to it for another day and test it some more to see if the light comes back on.

Sheesh.

 

Update: It has been a few days now with the new gas cap and the CEL has not come back on. I am hoping that the issue is resolved at this point. Although, I seem to be getting less than average gas mileage. I will post my mileage the next time I fill up but it looks to be less than 10 mpg. I drive very cautiously and accelerate slowly in a an effort to conserve gas.

 

Which engine? With an '03 it could be 4.7, 5.9 or Hemi... Also, 4x2 or 4x4? RC or QC?

Soft acceleration is always good, but I can tell you with a Hemi, it seems to like slightly higher RPMs. The engine makes better power at around 2000 rpm than it does down around 1500-1600 and I know when cruising around, the engine has a sweet spot between about 1900-2100 rpms that gets better gas mileage than when cruising at a lower rpm. My 4.56 gears really helped in that regard...

 

I have the 4.7L on my 03. It is the QC 4X2. I usually dont let the RPM's go much above 2k and like to stay around the 1.5K while cruising. Not sure if the excessive fuel consumption is due to any other problems that I might not be aware of.

Thanks.

 

A lot of guys start getting bad MPG numbers with 4.7s when they get some age on them. Do a search in thes section and the general discussion section, you'll see quite a few threads.

I have a 4.7, but the HO version in my Grand Cherokee. It went down a solid 4 mpgs, but that's because in my infinite wisdom, I decided one lifted, V8, 4x4 wasn't enough and had to lift my daily driver and stick bigger meats on it.

I have never seen where anyone completely solved the MPG thing. Most made it better with tune-ups, proper tire inflation, etc., but I don't think anyone completely got their MPGs back to where it was when they first got it.