misfire happening in my camaro

[BlackoutLFX]

Originally Posted by AKA-22

http://www.camaro5.com/forums/showth...08#post7408408

Must be a combination of no computer control below -14 degrees coolant temperature and winter gas...Just my opinion.

[hawkfe]

Had a CEL last month, codes was for misfires, had a different brand of gas then what I normally use and was cold out. Cleared the light and filled up with my normal brand, problem now is I can't pass my emissions. The following show NOT READY: EVAP System, O2 Sensor, and O2 Sensor Heater. Have no Codes and did the GM Drive Cycle, checked it after 130 miles and still have the Not Ready's. Will try some fuel treatment and see if that will help. Currently using the Trifecta tune.

[BlackoutLFX]

Originally Posted by hawkfe

Had a CEL last month, codes was for misfires, had a different brand of gas then what I normally use and was cold out. Cleared the light and filled up with my normal brand, problem now is I can't pass my emissions. The following show NOT READY: EVAP System, O2 Sensor, and O2 Sensor Heater. Have no Codes and did the GM Drive Cycle, checked it after 130 miles and still have the Not Ready's. Will try some fuel treatment and see if that will help. Currently using the Trifecta tune.

I think the trifecta tune turns off the rear o2 sensor. I would reload the stock tune for emissions test.

[Nutbutt]

Problem is getting the tests to enable when it's below freezing on start. This could be why you are not running the tests. Look at the GM drive cycle to enable and I think you will see the air and coolant temps are not allowing the tests to run.

[nikos30]

this happened when I was low on oil (cause it leaked out so slowly that I never noticed) AND when I had to replace my catalytic converter. good luck bro!

[greg_tolson]

Just got the diagnosis from the dealer. Since my vehicle is Direct Injection the valves in the injectors are never cleaned from the gas since it never passes through them to wash the carbon away (this is how DI vehicles work). The carbon had built up and kept causing my cylinder 1 to misfire (which they figured out since the movement of plugs/coils werent transmitting the misfire to other cylinders). They said the extreme cold would get the carbon stuck in the valve seats which would cause the misfire at cold starts. They recommend to me I use top teir fuel which btw I have been using ever since I've owned the vehicle (I'm a second owner after a year it was first bought, maybe the first owner used awful gas?), I generally go to shell or sunocco never those cheap-o places. I did use 87 octane for one year on the vehicle and swithced to 93 last year (Grade wouldn't be a factor right?). They also recommend that I use GM high quality fuel treatment every oil change. I have gone around the forum pages with this issue and have seen people write about this. They all talk about catch cans as a major limiting factor. Is a catch can really the best way to limit this issue?

[Nutbutt]

I had the same problem. Best advice is what they have told you plus a catch can. You can decide the best can since there are a lot of them out there. I currently running a mightymouse can because of my IPF SC. I was running a saikou Michi http://www.saikoumichi.com/ catch can before and I believe their catch configuration is the most efficient.
The real problem seems to be the combination of carbon build up and extreme cold weather causing this. The local dealership has had at least 2 LLT camaro, Cadillac cts, traverse a week for this issue. They are doing a upper induction cleaning (GM seafoam) and two treatments of fuel treatment.

[greg_tolson]

That is what they did to clean it out. They said my exhaust would smell for only a day or two. I asked the dealer their thoughts on the catch can and they told me that if im not racing the vehicle I dont need it. From the numerous stories I've read on here I've seen the oil build up people have in their catch cans and they are daily drivers like me. They made it seem like this dirty carbon build up could be a once in a while clean I'll have to maintain. They consider this problem not covered under the power train warranty yet there is nothing I do to the vehicle to cause this problem, i've always gone top tier gas stations. Since almost all cars are DI have you heard any of them getting issues like this at 38,000 miles?

[Nutbutt]

38k is pretty low but again at least at my local dealership there are 2013's coming in for this service. I still pretty much believe that the weather is making the problem worse and showing up quicker. But never the less the oil being ingested is still an issue that sooner or later would need to be addressed in service. As GM states it not covered under drive train so the customer eats it as routine service for DI outside of bumper to bumper mileage coverage.
The cost of a catch can is well worth it. But get one that is recommended and allows ease of access when mounted since it needs to be emptied at least once every oil change, an in colder weather a few more time depending on size of can.

[greg_tolson]

Had the CEL come on as i was on the highway last week. Didnt notice any sign of misfire, the light just came on and stayed on. Took it in and it drew the code P0430 which is catalytic converter issues. Getting the catalytic converter replaced on Friday which is covered on the 8 year 80,000 mile warranty. Was told the constant misfires made my cat go bad. I really hope this is the end of my constant CEL coming on.

[TooCool5]

Originally Posted by greg_tolson

Had the CEL come on as i was on the highway last week. Didnt notice any sign of misfire, the light just came on and stayed on. Took it in and it drew the code P0430 which is catalytic converter issues. Getting the catalytic converter replaced on Friday which is covered on the 8 year 80,000 mile warranty. Was told the constant misfires made my cat go bad. I really hope this is the end of my constant CEL coming on.

Have them clean the MAF also.

[Chevrolet Customer Svc]

Originally Posted by greg_tolson

Had the CEL come on as i was on the highway last week. Didnt notice any sign of misfire, the light just came on and stayed on. Took it in and it drew the code P0430 which is catalytic converter issues. Getting the catalytic converter replaced on Friday which is covered on the 8 year 80,000 mile warranty. Was told the constant misfires made my cat go bad. I really hope this is the end of my constant CEL coming on.

Glad to hear that the dealership was able to diagnose this concern. Please keep us updated on your vehicle's operation and don't hesitate to contact us privately with any further concerns.

William R.
Chevrolet Customer Care

[greg_tolson]

I am revisiting this thread because my car is back in the shop for misfiring issues againnnnn. What is different this time around is that it is the middle of summer versus the middle of winter. This has got me scratching my head. I had the car misfire on me while I was driving on the highway. I was cruising at 70mph and with living in Rhode Island the highways constantly are going down and up large hills. I was cruising up an incline that was probably a half a mile long and I could tell, being in 6th gear, the car was trying hard to get up it which caused my car to rock forward and back and eventually the car started misfiring and the CEL came on. Back in March they completely flushed the injector valves since apparent carbon build up caused the problem. Which with all the misfires caused my catalytic converter to go bad which needed replacement. I am so stressed now that I gave the car back to the dealer they aren't guaranteeing me it will be covered under warranty (since Im at 41,000 miles) yet this problem dates back when I had 35,000 miles. They also need the car to misfire for them to be able to diagnose it which I have no idea if it will misfire for them or not! And if it doesn't I'll have to pay for the rental car they gave me and diagnosis fee! I thought I was on to something with the engine being cold causing misfires in the winter time which it did. Now with the summer I have no clue when it will! I was able to drive the car after the misfire happened without any additional misfires (probably drove 20 miles). Is anyone having this headache??

[CamaroBC]

What's a MAF