2002 Mercury Cougar 2002 COUGAR CHECK ENGINE LIGHT CODES

2002 MERCURY COUGAR

70,000 MILES • 6 CYL • 2WD • AUTOMATIC

EKEISCH1

MEMBER
3 POSTS
FOLLOW

I recently bought an '02 cougar xr/35th anniiversary , 6 cyl with 70,000 miles.
The check engine light codes PO304, PO305, PO306, were on, which detected misfires of cyls 4,5,6. I changed the spark plugs, the wires and the coil. After clearing the codes few times, it still reads the same. Although am not a mechanic, have always
been a believer in good maintenace. Please tell me
what else it could be. Thanks, ED

Jan 16, 2008 at 11:13 AM

MASTERTECHTIM

CERTIFIED EXPERT
4,750 POSTS

you could have a vacuum leak on one cylinder head. try spraying carb cleaner around the base of intake manifold. see if the idle changes, you should be able to hear the change in idle if you have a vacuum leak. feedback greatly appreciated

Jan 16, 2008 at 11:26 AM

EKEISCH1

MEMBER
3 POSTS

We tried your suggestion spraying carb cleaner on the
base for the intake manifold 2x, but it did not make any difference.
My friend even asked about the rpms when it idles, and saw that it was good. Any other sugestions of why the check engine light is still on?
Thank you for you quick response from before!

Jan 18, 2008 at 5:05 PM

FLEXY5

CERTIFIED EXPERT
512 POSTS

Smack the injectors on cyl 4,5,6. A vacuum leak would also cause a lean code for that bank of the engine. Tap the injectors with a screw driver and see if that helps.
Dave

Jan 18, 2008 at 6:05 PM

EKEISCH1

MEMBER
3 POSTS

re: misfires on cyl 4,5,6 after doing my thorough
investigation to no avail, about a week ago, I read
that someone for a similar problem disconnected the negative battery cable, so...... I tried it and THE CHECK ENGINE LIGHT HAS NOT COME ON SINCE!!!!!
All seems to be working fine as it did before !!
How come??

Mar 23, 2008 at 6:18 AM

MASTERTECHTIM

CERTIFIED EXPERT
4,750 POSTS

i have never heard of that before. i will keep it in mind

Mar 23, 2008 at 11:11 AM