2002 Chevy Trailblazer

[Tish]

My SUV's "Check Engine Soon" light came on and my vehicle started running rough. Then the light would flash off and on. Did an OMB II diagnostics on it which read Cylinder 2 misfire. Swapped Cylinder 2 & 5 coils and 2 & 3 plugs to see if the reading would be on Cylinder 3 or 5. Can't get a reading now.

Can anyone tell me what could be the problem? I was already told it could be anything from the injectors, spark plugs and wires, or cylinders.

 

[BRomanJr]

My SUV's "Check Engine Soon" light came on and my vehicle started running rough. Then the light would flash off and on. Did an OMB II diagnostics on it which read Cylinder 2 misfire. Swapped Cylinder 2 & 5 coils and 2 & 3 plugs to see if the reading would be on Cylinder 3 or 5. Can't get a reading now.

Can anyone tell me what could be the problem? I was already told it could be anything from the injectors, spark plugs and wires, or cylinders.

First off, Welcome to the Forum.



Please provide information about your vehicle (some can be put in your profile) including mileage, Maintenance history.


Worn out plugs are the most likely cause of your issue.
Coils can fail, There are no "spark plug wires" on the I6.

You will get more responses with more info.

 

[meerschm]

since you cannot get a reading, is the OBD connector loose, or did you blow a fuse?

good thinking to switch and isolate.

if you need plugs, the 41-103 AC Delco plugs have a $2 each rebate, you can find them on amazon with free shipping. recommended over 100k miles.

 

[The_Roadie]

On the "can't get a reading" issue, is your check engine light now off, or does the code reader not light up when you plug it in to get the exact code? If it's the latter, you've blown front fuseblock fuse #13.

The Owner's Manual has a caution about a flashing CEL indicating a misfire. Its says stop driving ASAP. The reason is that a misfire can send unburned fuel through the cylinder, which will ignite in the catalytic converter, and damage the cat. Replacing it is much more expensive than troubleshooting the misfire in a structured way.

As has been mentioned, if the plugs are over 100K miles, they're suspect. Next the coils. The wells where the coils seat down on the plugs can also fill up with oil or water from leaky gaskets, causing a misfire. Worst of all is low compression in a cylinder, which can be found in a compression test, and that's big $$.

Good luck. Share more information and we can help out with more accuracy. Welcome!

 

[Tish]

The Check Engine Soon light came back on and the diagnostics stated Cylinder 5 this time which was originally Cylinder 2 before it was switched. Hence, the problem is in fact Cylinder 2 needing a Coil.

Thanks to Everyone who responded to my question! Tish

My SUV's "Check Engine Soon" light came on and my vehicle started running rough. Then the light would flash off and on. Did an OMB II diagnostics on it which read Cylinder 2 misfire. Swapped Cylinder 2 & 5 coils and 2 & 3 plugs to see if the reading would be on Cylinder 3 or 5. Can't get a reading now.

Can anyone tell me what could be the problem? I was already told it could be anything from the injectors, spark plugs and wires, or cylinders.

 

[The_Roadie]

Thanks for the report back. We love to help out. Did you by any chance check out Trailvoy first and not get any answers? That site is higher for searches, but the community here is the source of all the postings over there, until the new corporate owners started throwing too many ads in our faces and we all left in protest about a year ago.