[Rookie]

Shows to be my first post but actually a long time member that forgot his password a few months ago. Couldn't get a mod to help me reset it so i just made a new account

Looking for advice as to what could be going on with my car. A couple days ago i went to start it and was getting a horrible misfire. Car was jerking around and sounded horrible! SES light popped on and started smelling a strong odor of fuel. I pulled codes and got a P0305 (cyl 5 misfire). I proceed to drive to work very carefully and notice half way there (now that the engine is warmed up) it is running fine. I get to work,clear codes, pull cyl 5 coil, swap to cyl 1 and everything seems to be fine except now im getting a oxygen sensor lean code that is popping up. This morning i go out for another cold start and it is running extremely bad now. Pull codes and getting p0304,p0305, and p0306 codes now (cyl 4,5,6 misfires).

My #1 theory is my oxygen sensor is either failing or is broke. I had my downpipes taken out and factory cats put back in a few months ago. The fact that i got a oxygen sensor lean code has me thinking it is putting more fuel in those cylinders ultimately causing a misfire in those particular cylinders. And please correct me if i am wrong, but i do believe bank 2 sensor 1 is for cyl 4,5,6?

My #2 theory is injector #5 is stuck open. but then why would i get misfires on 4 and 6 now.

note: i have not pulled the plugs yet because i dont have the tool. just ordered one from bms about 30 mins ago. The car still runs right after warm so im guessing they are not completely fouled, just probably black as hell.

Thanks in advance for any help or ideas, im just about ready to pull my hair out with this

[Ingeniator]

Originally Posted by Rookie

Shows to be my first post but actually a long time member that forgot his password a few months ago. Couldn't get a mod to help me reset it so i just made a new account

Looking for advice as to what could be going on with my car. A couple days ago i went to start it and was getting a horrible misfire. Car was jerking around and sounded horrible! SES light popped on and started smelling a strong odor of fuel. I pulled codes and got a P0305 (cyl 5 misfire). I proceed to drive to work very carefully and notice half way there (now that the engine is warmed up) it is running fine. I get to work,clear codes, pull cyl 5 coil, swap to cyl 1 and everything seems to be fine except now im getting a oxygen sensor lean code that is popping up. This morning i go out for another cold start and it is running extremely bad now. Pull codes and getting p0304,p0305, and p0306 codes now (cyl 4,5,6 misfires).

My #1 theory is my oxygen sensor is either failing or is broke. I had my downpipes taken out and factory cats put back in a few months ago. The fact that i got a oxygen sensor lean code has me thinking it is putting more fuel in those cylinders ultimately causing a misfire in those particular cylinders. And please correct me if i am wrong, but i do believe bank 2 sensor 1 is for cyl 4,5,6?

My #2 theory is injector #5 is stuck open. but then why would i get misfires on 4 and 6 now.

note: i have not pulled the plugs yet because i dont have the tool. just ordered one from bms about 30 mins ago. The car still runs right after warm so im guessing they are not completely fouled, just probably black as hell.

Thanks in advance for any help or ideas, im just about ready to pull my hair out with this

Sounds like you might be on the right track. You could try swapping o2 sensors from Bank1(123) to Bank2(456) you only need to swap the pre-cat wideband sensors not the narrow band. If the codes don't move I would be with you on the stuck injector. 5 can cause 4/6 misfires due to overlap. However stuck injectors normally don't cause lean codes.

[Rookie]

Ya that is what i was thinking as well. If the injector was stuck open i shouldn't be getting o2 lean codes. Im banking on the o2 sensor and i like your idea of swapping them. I will probably go that route and hope all the codes switch over to 1,2,3

[Rookie]

Also, can anybody confirm what primary sensor controls cyl 4,5,&6? I know it is the front sensor but is it the one on the pass side or driver side?

that would help me out alot! thanks again

[chili36]

Originally Posted by Ingeniator

Sounds like you might be on the right track. You could try swapping o2 sensors from Bank1(123) to Bank2(456) you only need to swap the pre-cat wideband sensors not the narrow band. If the codes don't move I would be with you on the stuck injector. 5 can cause 4/6 misfires due to overlap. However stuck injectors normally don't cause lean codes.

This.
Keep in mind that one sensor is shorter than the other one.
You'll have to re-route the wire in order for it to reach the connector.

[Ingeniator]

Originally Posted by Rookie

Also, can anybody confirm what primary sensor controls cyl 4,5,&6? I know it is the front sensor but is it the one on the pass side or driver side?

that would help me out alot! thanks again

Passenger side is bank 2. Rear turbo downpipe routes to passenger side.

[Rookie]

Originally Posted by Ingeniator

Passenger side is bank 2. Rear turbo downpipe routes to passenger side.

Thanks for all your help man, really appreciate it

I will let you guys know what happens... fingers crossed lol

[Rookie]

Well, the oxygen sensor did not fix the problem Went ahead limped it to the stealership this morning. Weird thing is, that after i installed the new sensor yesterday the car was running perfect. I even went out late last night to start it and she was purring like a kitten. Wake up this morning and boom! cyl 4 and 5 misfires. Its almost like its on a timer and can only take a shit at exactly 7:25am...uggghhh .... Should know shortly and i will update.

[techwhiz]

Injectors.
Leaky injectors will dump residual fuel in the cylinders overnight.
Warmed up the car will do fine.

In the morning it will run like a truck with a bad plug. Been there, done that.
Replaced all six injectors under CPO.

[Rookie]

Originally Posted by techwhiz

Injectors.
Leaky injectors will dump residual fuel in the cylinders overnight.
Warmed up the car will do fine.

In the morning it will run like a truck with a bad plug. Been there, done that.
Replaced all six injectors under CPO.

Yes sir, just ordered my injectors and having them put in tomorrow. Hope im not burning my self for just doing 3

[Jeff@TopGearSolutions]

Originally Posted by techwhiz

Injectors.
Leaky injectors will dump residual fuel in the cylinders overnight.
Warmed up the car will do fine.

In the morning it will run like a truck with a bad plug. Been there, done that.
Replaced all six injectors under CPO.

That's what I was going to say.

Originally Posted by Rookie

Yes sir, just ordered my injectors and having them put in tomorrow. Hope im not burning my self for just doing 3

As long as you realize the other 3 may go down the road it won't burn as bad.

[TheM3Boy]

I am having the exact same problem for nearly a year now and have been putting off the repair but will have to bite the bullet and replace them..... or get them cleaned.
I have seen the post about cleaning/refurbishing the injectors and looks like people are happy with ***********. I am waiting on his response if he ships to Canada.
Does anyone know of a similar service in Canada in case he doesn't ship here?

[Rookie]

Replacing 3 injectors did fix the problem. I was thinking about sending out the bad 3 to have them refurbished for when 1,2,3 go out.

[Mike@N54Tuning.com]

Originally Posted by Rookie

Yes sir, just ordered my injectors and having them put in tomorrow. Hope im not burning my self for just doing 3

I think its okay to just replace the 3 faulty ones. Just realize you may need to do the other ones at some point.

Mike