[Hawk8]

Check engine light is on and when check by AutoZone received 0300.0303.0304 codes. 83,500 miles on engine. I change the oil regularly. Could it be the fuel I use as suggested by the manual or could it be the plugs (due at 100,000 miles), the coils or the3 convertor gone bad.

 

[Submariner409]

Not the fuel, particularly if you run the recommended octane Top Tier stuff. Torque converter ? Nope.

The indicated cylinder miss points to either a coil, boot, plug or combination.

Oil should not affect a cylinder miss, and the 7,500 - 10,000 oil/filter change interval is just fine. Do you use the OLM ?

Welcome to the Funny Farm !!!! :highfive: I'll move this up to the later STS forum - it's more "alive" than this engine forum.

 

[Guest]

Codes indicate a misfire on cylinder's 3 & 4. Most likely coils. You don't indicate weather yours is a V6 or V8? The 2008 V6 DI had inferior Bosch coils which frequently fail. I replaced all of mine including new plugs. If you continue to drive it you will destroy your CATs

 

[1BadCadSTS]

Codes indicate a misfire on cylinder's 3 & 4. Most likely coils. You don't indicate weather yours is a V6 or V8? The 2008 V6 DI had inferior Bosch coils which frequently fail. I replaced all of mine including new plugs. If you continue to drive it you will destroy your CATs

Having two coils go on completely opposite banks at the SAME time? Very unlikely.

I'd check your oil level...

 

[ECha3]

My first thought was V6 & low oil level; very common in both V6 VVT & that DI in particular.

1Bad, I didn't know the DI coils were junk. I knew they had little more torque than the older V6's; why do so many forget? They coulda' had a V8!

 

[1BadCadSTS]

My first thought was V6 & low oil level; very common in both V6 VVT & that DI in particular. 1Bad, I didn't know the DI coils were junk. I knew they had little more torque than the older V6's; why do so many forget? They coulda' had a V8!

Honestly in 120k miles the 05 SRX 3.6 in the fam had 1 coil get weak. I've never heard of a coil problem on the 3.6s (they have so many other problems though...). As I said though. The odds of 2 failing at the same time on completely different banks...I really doubt that.

Either he's low on oil and it's screwing with the VVT or he was/is low on oil and the timing chains decided to not play well with the guides and sprockets. Of course this is all a conspiracy though and 3.6s are not prone to this...

 

[curtc]

1st gen 3.6 CTS owners report coil problems regularly, definitely not two at once though. Although not impossible, just not too likely.

 

[Hawk8]

Hello everyone update to previous post. I ordered and changed all sparkplugs and coils. When I went to the parts store to try and remove the check engine light the 0300 code was still showing up. All plugs excerpt one had white tips. one had black deposits. Also the vacuum hose that runs from front of the throttle body to the firewall into the cover smell of gas and was wet with oil. Any one have any suggestion or remedies? Currently mileage over 90,050 miles