QuestionQUESTION: I have a 06 g6 with 2.4l engine, idles good but its bogging pretty bad and engine light came on I took the codes p0300, p0101, and p0326 knock sensor, random misfire and mass air flow, so I cleaned the maf replaced spark plugs and air filter and erased codes and went for a ride and the knock sensor and random misfire came back, however the car ran a little bit better but not much. I dont have much money too take to the dealer so is there any way to test the catalitic converter or is this an air leak possibly? The vaccuum was about 18hg but had very slight high speed fluctuation, want should I try next? Thanks for any help
John
ANSWER: Hi John:
the ecotech engine is notted for coil and or ignition module issues. either one of them goe bad and you wind up loosing 2 cylinders at a time. the coils are paired up on the older ones each coil runs 2 cylinders. so you could have a bad coil or ignition module. the module is replaceable seprate from the coil pack. on the newer ones the module goes bad more oftenthen the coils on the older ecotech engines the coild went bad. take the module off the top of the coils pack and take tito one of the big box auto parts stores some of them have the amility to check them for you to tell you if it's bad or not if it's bad then replace it if it tests it's a good good chance the coil assembly is bad but it's a guess. The MAF sensor code may be set by the misfire and the erratic vacuum can be an end result for the misfire as well not an indication of a mechanical issue. The knock sensor code may just be an anomoly.
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QUESTION: Thanks for the reply, this engine has 1 coil per cyl with plug boot underneath for spark plug, can't see how it would run more than one cyl. Is there an ohm value for coil? could I check them cold vs hot and see if there is a swing in ohms would that determine if has high resistance and therefor faulty? also my purge control valve is open at idle when hot so there is full vacuum going to can underneath- is this normal? Near pulling my hair out and still owe $7000 on this peice, any more help or tests I can perform would be greatly appreciated.
Answer•Turn ON the ignition.
•Inspect the fuse that supplies voltage to the ignition coil/modules.
⇒ If the fuse is open, then test the spliced circuits and the individual ignition coil/modules for a short to ground.
•Disconnect the affected ignition coil/module.
•Connect a test lamp between the ignition coil/module ignition 1 voltage circuit and a good ground.
•With the test lamp still connected, measure for battery voltage between the ignition 1 voltage circuit and a good ground.
⇒ If the voltage is not within 1 volt of battery voltage, repair the high resistance or the open in the ignition 1 voltage circuit.
•Turn OFF the ignition, and all electrical accessories. Allow sufficient time for all of the control modules to power down before taking a resistance measurement.
•Measure for a proper value of less than 5 ohms of resistance between the ground circuit of the affected ignition coil/module and a good ground.
⇒ If the resistance is more than 5 ohms, repair the high resistance or the open in the ground circuit.
•Exchange the affected ignition coil/module with the ignition coil/module of a good cylinder.
•Start the engine and observe the scan tool.
⇒ If the misfire transfers with the suspect ignition coil/module, replace as needed.
⇒ If the misfire does not transfer with the suspect ignition coil/module, observe the component testing procedures below, and replace the spark plug if needed.
Component Testing
• Use the Spark Plug Inspection procedure to verify the integrity of the spark plugs. Refer to Spark Plug Inspection .
• Use the J 26792 Spark Tester to verify the output of each ignition coil/module
As the purge valve the computer controls the on time for it if you unplug the electical connetor to it and it still is pulling vacuum from the canister then the vlave is stuck open other wise don't worry about it.
