[Jay D]

It was running fine until I put 9 gallons of gas in it. Mech from Chevy dealer say lower intake manifold is bad and needs $1,600 worth of repairs.

Check engine light on with the following codes P0171 & P0300. No other symptoms are apparent.
Vehicle is idiling rough at stop lights. Egine seems fine under load.

 

[COLD STEEL]

Im not on my mastertech device at the moment but if I remember correctly, po171 is o2 sensor and po300 is random misfire. That tells me you got some bad gas if this happened after filling up. Not to be an ass but are you sure you put gas in it? I know some stations have multi pumps and sell diesel. Either way I would drain the tank,new fuel filter and reset the computer.

The intake gasket is common if you have a 3.4/3.8L and the price he quoted you is about 900-1000 over what it should cost.

 

[x_sgs_x]

If he put diesal in it, he wouldnt have made it home.

 

[COLD STEEL]

If he put diesal in it, he wouldnt have made it home.

I think you meant DIESEL, and depending how much GAS was in there, it would have mixed and its possible it would have run around....it would have run poorly (po300) but still possible to run. We can only do so much from hearsay and not actually being able to see the car first hand

 

[04DetroitLS]

LIM gaskets are about $60 for the alum ones IIRC (zzp/intense aka green ones)
fairly easy to replace yourself

if the O2 is bad, add another $100 fr the primary, $60 for the rear also fairly easy to replace.
do yourself a favor, find an 06 buick lucerne in the J/Y, grab the UIM/LIM from there (should be about $100 ttl) and replace yours w/ those... problem solved, no more plastic UIM/LIM to worry about..


Or, if you really want, I'll sell you my UIM/LIM (stock 04 3.8 w/ about 20k on it) for $60 shipped youll jut need the LIM gaskets

 

[COLD STEEL]

LIM gaskets are about $60 for the alum ones IIRC (zzp/intense aka green ones)
fairly easy to replace yourself

if the O2 is bad, add another $100 fr the primary, $60 for the rear also fairly easy to replace.
do yourself a favor, find an 06 buick lucerne in the J/Y, grab the UIM/LIM from there (should be about $100 ttl) and replace yours w/ those... problem solved, no more plastic UIM/LIM to worry about..


Or, if you really want, I'll sell you my UIM/LIM (stock 04 3.8 w/ about 20k on it) for $60 shipped youll jut need the LIM gaskets

thats a deal, buy buy buy

 

[04DetroitLS]

i got a freakin garage full of L36 parts that'll prob never see use again :biggrin:

UNLESS i go snailpower, but thats why im holding out on selling my L26 parts LOL