Check Engine with 0456 and 2106

[CUAviator]

Hi all. I’ve got a 2003 qc with the Hemi. Just today my check engine light came on (steady, not flashing). I did the key trick to check the codes and both 0456 and 2106 came on - evap issue and ETC. There are no other lights (I see people mentioning a ETC light) and the truck drives fine.

About 4 weeks ago I did some Seafoam into the throttle body, 2 weeks ago I got the oil changed, and last week I put some Gumout fuel system cleaner in. It has been over a week since all of that but I’m wondering:
A) would any of that have anything to do with these codes
B) does the combo of codes signify anything
C) Is there something I can do/look at/fix before I take it to the shop?

Thanks in advance.

 

[MADDOG]

Easy things first:

Check your gas cap. Make sure it's tight and the seal is good. That's the most common cause for a P0456. If it looks good, then you have a small leak somewhere in the fuel evap system. Most common issue is a dried out rubber hose that has cracked.

The P2106 can be caused by several things. If you seafoamed the engine did you replace your PCV and EGR valves? One or both of them could be clogged up now. Also, make sure your throttle body valve opens and closes fully. Also make sure the electronic connection to the throttle body is clean, not cracked or loose.

Good luck!

 

[CUAviator]

Easy things first:

Check your gas cap. Make sure it's tight and the seal is good. That's the most common cause for a P0456. If it looks good, then you have a small leak somewhere in the fuel evap system. Most common issue is a dried out rubber hose that has cracked.

The P2106 can be caused by several things. If you seafoamed the engine did you replace your PCV and EGR valves? One or both of them could be clogged up now. Also, make sure your throttle body valve opens and closes fully. Also make sure the electronic connection to the throttle body is clean, not cracked or loose.

Good luck!

Thanks for the info. First, I'm wondering if I popped the 2106 when I performing the seafoam treatment. As for the 0456, it just happened to be hot the day i got it...I'm wondering if the gas expanded and pushed the fuel cap off a little. When the scanner read the codes, the only thing that showed up was the 0456. The next day, it was cold, no light. A few days ago, it was hot again (80s) and I new I was going to get the light...and I did. Then it was, and has been cold ever since...no light. Ergo, may I just need a new gas cap?

 

[xtremewlr]

Wouldn't hurt to get a new cap.

I agree with replacing the EGR valve and the PCV valve, especially if you don't know the maintenance history on the truck from before you owned it. I think the 03 is similar to my 04 with the EGR valve on the front passenger side head. Has a tube that run up to the back of the intake manifold, right next to the PCV valve, which is also in the intake manifold. Be sure to clean that tube out as best you can when you replace the EGR valve.

 

[CUAviator]

Wouldn't hurt to get a new cap.

I agree with replacing the EGR valve and the PCV valve, especially if you don't know the maintenance history on the truck from before you owned it. I think the 03 is similar to my 04 with the EGR valve on the front passenger side head. Has a tube that run up to the back of the intake manifold, right next to the PCV valve, which is also in the intake manifold. Be sure to clean that tube out as best you can when you replace the EGR valve.

Quick question, what is the part with the yellow arrow point to it in this pick - I have a K&N cai. The indicated part had popped out of the tube (don’t know how long it was out, I noticed it when I went to do the sea foam treatment...and was the day before the check engine light -2106). As for maintenance history, I have owned this baby since Aug 2003 when there was less than 1 mike on it![emoji106]

 

[xtremewlr]

Quick question, what is the part with the yellow arrow point to it in this pick - I have a K&N cai. The indicated part had popped out of the tube (don’t know how long it was out, I noticed it when I went to do the sea foam treatment...and was the day before the check engine light -2106). As for maintenance history, I have owned this baby since Aug 2003 when there was less than 1 mike on it![emoji106]

IAT sensor (intake air temperature). Having it pop out shouldn't affect things too much. You will get some unfiltered air in via the sensor hole but the motor would have run normally. I doubt it would have contributed to the CEL. I'd try resetting the PCM by disconnecting the positive battery terminal, grounding that to the negative side, while you replace the EGR and PCV. At least for 5 minutes.

 

[chrisp2493]

2003 doesn’t have EGR on it so that shouldn’t be an issue. That sensor being out will mess with the engine, I’ve started the truck after I forgot to plug it in and it was really erratic. The evap is almost definitely a rotted out hose near the charcoal canister. The computer randomly checks the system for leaks, that’s why the code will come and go

 

[MADDOG]

It just might be the gas cap. On hotter days the fuel vapors will expand. If the cap doesn't seal tightly due to the increased pressure, then it causes a leak which the system could diagnose as an EVAP system leak.

 

[CUAviator]

It just might be the gas cap. On hotter days the fuel vapors will expand. If the cap doesn't seal tightly due to the increased pressure, then it causes a leak which the system could diagnose as an EVAP system leak.

That’s what I’m thinking. It will literally go from 40 deg to 79 the next day. The second time that happened, I knew I was getting the light. That night it dropped back to 40 and hasn’t got warmer than 56...no light.