I have a 2004 DII, S with 40K miles that just had the 60k done by a local shop (non-LR dealer). DENSO platty plugs were used since the original Champion plugs don't exist in addition to all services listed in the owner's manual (transmission / brake flush, etc.). Also had new pads and rotors installed using original LR factory parts.

After about 20 miles of driving, the service engine light turned on. I plan on bringing back to the shop shortly and know that there are a million reasons this light can turn on, but anyone have any theories?

 

Nope, not until we have the codes.

 

Find a local parts store, some will still read the codes for free, get us the 4 digit numbers and a break down on what exactly he did.

 

Went to Advance Auto Parts and they check the codes. Here's what showed up: P0442 "Evap emissions control systems leak (small)".

The store thinks this could be from the gas cap being loose or adjustments made during the 60k service a couple days ago. He thinks it will go away in a couple days on its own.

I've had this problem with the gas cap seal before and once the dealer had to have the thing replaced under warranty, so this code reading makes sense. What you guys think and why does this keep happening?

 

Well if your gas cap is tight then it is prob a evap leak in the fuel return line/purge valve.

 

No body has verified it is the cap yet, get it checked cause there are a number of evap related parts and hoses that cause this to happen, and the cap is not the usual cause, just always gets blamed for it.

 

Ok, thanks. I will get the engine light checked ASAP. If it's not the gas cap, but rather another evap related part, is this serious?

Is it possible that in the process of the 60k service the mechanic did something to trigger this light. If yes, this is another reason for me to just pay the extra cash and go to the dealer for service and avoid all this damage control...

 

No the 60k did not trigger this unless the mechanic dumped some injector cleaner into your gas tank and he did not replace the gas cap tight enough.
Just take it back to him and play dumb, "hey you worked on my truck Fri. and now the check engine light is on, can you help me?"

 

That's what I did Spike and they found the same evap code that Advance Auto Parts did. They "smoked" the system to find any leaks and didn't find any. They attributed the light to a possible loose gas cap. They reset the light and everything seems to be in order.