I just replaced my intake gasket on my 98 ford mustang, 3.8L, It was running ok before, other than oil in my coolant. Now it idles rough. I borrowed a scan tool and it comes up Code 1151. Could this be the O2 sensor or what?
Year : 1998
Make : Ford
Engine: 3.8 V-6
Scan tool comes up 1151, Air fuel Mixture
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The code P1151 0ne in most cases is caused by a vacuum leak, are you sure you didnt miss any vacuum lines and or got a good seal on the new gasket?
I have gone over it many times
If the intake is leaking would it come up the same
Yes this is a lean code, have you tried spraying around the intake with some carb cleaner.
No, I will give it a try.,
will the RPM increase if it is leaking?
No in most cases it will slow down. Also are you sure you got your firing order correct?
Yes but will double check it.
Ok do you need the firing order diagrams?
I checked the wires, OK, I sprayed carb cleaner around lower and upper intake and it did not respond.
I checked the plug wires they are good
I tried spraying carb cleaner and it fine but now its comming up code po305
If it idled rough, its either missing due to a bad spark plug, a vacuum leak and/or low compression. Recheck your spark plugs for proper gap and no fouling. Yes, if the intake is leaking inside, it could be the same. This is a lean code. If it was ok before, then its likely something you did on the install.
OK , Thanks for you input.
You're very welcome. Thank you as well.
23 years with Ford specializing in drivability and electrical and AC. Ford certs and ASE Certs