Byways not Highways: Gen 3 2004 Montero Limited Build

[haolepinoy]

I'm having this same code on my 2006. It will trip the CEL if it's logged as pending and it is detected again. It happened to me the other day, was pending, I started the truck to warm it up and when I got in to drive off, the CEL was on. I need to get this one figured out too.

Phil from JDM Journeys and PajEvo #581 fame recommends over at the ADD forum checking the fuel filler neck if you're getting a P0456 code. It looks like both Jason and AJM are in Pennsylvania, aka the rust belt, so it very well could be possible that you've got some corrosion-related pin holes in the filler neck. Andrew and Brad from Auto Off Topic have talked about this common rust belt issue a number of times as the first thing they suspect after the fuel cap when it comes to checking for evap leaks.

 

[nalong55]

I am not running an OEM thermostat, but the cooling system is operating correctly - you can watch the temperature regulation and and verify closed loop fuel control using Torque. There are a couple of Mitsubishi TSB on this issue, TSB# 0313001 published 1/1/03 and TSB# 181505 published 4/1/05. A quick google will give some details, but the short version is that under load, in cold weather, the initialized values in the ECU don't work correctly. So, for example, if it's below freezing out and I jump on the freeway going up into the mountains the computer thinks the temperatures are all out of wack, even though they aren't. The fix is a ECU reflash to change the temperature limits, it's just ~$200 bucks at a dealer to get it reflashed, so I haven't done it yet...

Correct, I am having the same issue and this was available under warranty, however I am now WELL outside of warranty and do not want to spend $200 to fix the CEL even though nothing is wrong..

TSB-03-13-001 Mitsubishi Technical Service Bulletin

TSB-03-13-001 Mitsubishi Technical Service Bulletin

www.tsbsearch.com