I wrote a few weeks ago about issues I was having with gas milage. My 03 disco will have the service engine soon light go on and off at times making it hard for me to get codes. Well, it went back off today and I went to Advanced Auto Zone to have them checked.

This is what codes it put out: P1412, P1415, P1300, P0308, P0305.

I have had the head gaskets replaced earlier this year. The engine light started coming on about 2 months ago but would go off after the car rested. It would run great for a week and then it would have hesitation when giving it gas from a red light. It is also making a big sucking noise coming from the gas cap every 15 to 30 seconds.

Any suggestions / thoughts would be great.

 

The 1412 and 1415 are SAI codes. it is most likely the $25 SAI vacuum solenoid that was the culprit, could be the hosing though since you said you are haring a vacuum leak, the solenoid takes about 10 mins to install. The others codes are misfires. Check for vacuum leaks in your intake and make sure all clamps and hoses are tight. What wires do you have installed?

 

With having the heads done recently, what plugs and wires did you install?

 

I just took a look and didn't see a brand name. The wires are gray with the words SUPPRESSION - 2015 SILICONE. They look like they were not replaced when they did the head gasket. Let me get back to you on the plugs. Ill have to take one off and the engine is still slightly hot.

Where can i get this SAI vacuum solenoid? The loud noise on start up and air being sucked into the gas tank is getting annoying. I did changed the filter on the SAI but they didnt help at all.

 

I tried to take one of the spark plugs off but it seems I cant take the wire off of the plug. I dont want to pull or do something wrong and break the #2 wire/plug connection. Any tips on how to go this. Ive got a garage full of tools...just new territory for me.

 

You need to start with new plugs and wires. I like the Bosch Plat +4 (amazon.com) and the Magnecore (from apexperformance.net) some people will say otherwise Iridium Plugs and Kingsborne wires… either way you need 8mm wires and new plugs. Then clear your codes and get the remaining codes and come back to us.

 

Twist the wire boot until it rotates before you try and pull the wire off. When installing wires, use some die electric inside the boot and some anti-sieze on the plug threads.