Couple code's..

[Bamfster]

Intake gaskets dry out and cause a vacuum leak ... very common for high mileage engines.

 

[Swetrid]

Intake gaskets dry out and cause a vacuum leak ... very common for high mileage engines.

Second that one, if you cant pcv hose leak it will be lower intake gaskets. Intake gaskets usually only show up when its cold out.

 

[77mud]

The engine itself has about 200k on it, but had a new intake put on it about a 100k miles ago due to a crack in it.

 

[77mud]

I picked up some MAF Cleaner today, when ever she gets off ill swing by and clean it. If that doesn't do it I guess she will have to take it somewhere, Im not feeling up to pulling the intake on it if that is the cause, these newer vehicles aren't anything like my old school engines that Im always tinkering with.

 

[77mud]

also i should add the Dealer did the engine swap, and the dealer did the cracked intake swap.

 

[77mud]

Okay... Cleaned the Maf Monday, she has drove the expo to work and back 2 times so prolly a 100+ miles and no SES light yet.

 

[hortonguy]

if you have acess to live data you can pull up both o2 sensors and watch them and use a can of carb cleaner and spray downn all vacume hoses and conections and the intake when you find the vacume leak the o2s will flat line lean and the engine idle will go up.

 

[77mud]

been over 500 miles put on it and no light. She had it Inspected today, and In NC you must pass what they call a Emission's test were the put it on the computer and it checks every thing. also pulls any code's that are on the car or pending, It passed that aswell. So pretty confident it was just a nasty MAF.

 

[mrazndead]

yes I had same deal. maf. thanks to lanes24 tutorial it saved me,

 

[Rosin]

Lane24 has it right. On my '99 4.6, the PCV hose completely rotted out, causing my engine to idle roughly and occasionally stall out when stopped. It did, however, cause a "System too lean" code. If you're getting a trouble code without any actual trouble, to me that seems like a problem with the sensor. Also, I'm just theorizing here; maybe somebody else can correct me. But couldn't "System too lean" also indicate a lack of adequate fuel flow, possibly caused by clogged injectors or a dirty filter? Filters are cheap and fairly easy to replace (make sure you depressurize the system first), and clogged injectors can sometimes be cleaned up by running a can of Seafoam or some other injector cleaner through the system.