# 1997 Quest OBDII code 0306



## LeeBowman (Apr 20, 2008)

I have a 1997 Quest GXE, 180,00 miles, that gets a P0306 code intermittently.

Recent work done: Replaced plugs, wires, rotor and cap. It starts/ runs fine, but gets this code on occasion. I have not been able to re-license it due that reoccurring problem (Arizona strict about codes).

The code is defined as "misfire 1-6" or "misfire cylinder 6". I have also seen it listed as "EGR excessive flow detected" (which one valid?)

I have had the EGR valve off, cleaned it, tested its vacuum function (diaphragm moves when vacuum applied).

Also, I have run compression checks on all cylinders. I believe they were within spec (~ 100 psi?), but perhaps maginal. I will recheck. Also, neither catalytic converter ever replaced. Should I do a temp check to see if high temp is achieved?

So, it seems to run OK, don't hear a misfire, but the code says so. Could it need a valve job (or rings?) Thanks for any comments!


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## rogoman (Dec 16, 2004)

A P0306 OBDII code is a: cylinder 6 misfire detected.

I'm not that familiar with the VG30E motor. If it uses individual ignition coils for each cylinder, then the coil may be marginal in cylinder #6.

A compression reading of 100 psi is low. When doing a compression test, make sure the throttle valve is fully open.


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## LeeBowman (Apr 20, 2008)

*more ...*

_"If it uses individual ignition coils for each cylinder, then the coil may be marginal in cylinder #6."_

It has a distributor and one coil, plus a power transistor which is triggered by an amplified pulse from an inductive pickup (rather than points). I believe that the same code was present both before and after the rotor, cap, plugs and wires were replaced.

After those replacements about 6 mo back, I drove it around town and on the freeway, and the code went away. I parked it for 6 mo, recently drove it again, and the code is back. At this point, I may have to take it to a repair shop for assessment (or repair), since my temp driving permit will end in three days. I'll recheck the compression tomorrow as well.


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## rogoman (Dec 16, 2004)

Here's some info about DTC codes P0300 - P0304 that I copied from a 1998 240SX FSM. Even though it's a different car, the standard universal OBDII diagnostic procedures should apply to your car.


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