1996 Tahoe code P306 Help please!

[CENA]

I have 1996 Tahoe, my engine light came on and the code is P306, there is a couple of possibilties with this code. Misfire, fuel pressure other ones I can't remember off hand. The light has come on before and then has gone off. This has happened a couple of times. It seems to happen when I pull my snowmobile trailer or shortly after. The vehicle seems to start rough as in really kicks in when you turn the key. (not prompltly though when cold). When warm starting is smooth. Does not have a rough idle or anything like that. Runs great. Any ideas? Thanks for any info!

[MT-2500]

The code indicates a miss fire on no 6 cylinder.
Does the check engine light blink on the road?
How many miles on plugs and tune up stuff?
Any other codes?
MT

[CENA]

The light has blinked once before. It is off now again. Went off after two days. No other codes, just that one. I was going to change the plugs. But they are 40 bucks. Just didn't want to have to change them if not needed.

[maxwedge]

So how old are the plugs and wires , first thing that would cause this.

[CENA]

I do not know. I just purchased this vehicle 2 months ago from a dealership. Of course they said everything was checked. Yeah right! I already had to replace the intake gasket after 2 weeks of owning it. No warranty of course! There is 96,000 miles on it. So, you think I should change the plugs and wires? You don't think it is a fuel issue, such as pump, spider, regulator or something?

[MT-2500]

Engine light blink and miss fire code right.
As Maxwedge said plug and wires check or replace first thing.
Along with fuel and air filter check or replace.
On the spark plugs use only AC Delco that the latest AC delco spark plug book calls for.
The plug no and gap has been updated on a lot of them.
So always check for the latest info and specs. on them.
Along with fuel and air filter check or replace.
If you can do it yourself or if no find a good repair shop.
Let us know how it goes.
Check around Ask around
Word of mouth.
Family friends coworkers neighbors business people and delivery people.
Mailmen and parcel delivery people get around and notice a lot of stuff.
Even a good parts house knows what shops are good and not good.
Chamber of commerce and better business bureau and city hall.
If you find a good referral to a repair shop go look them over and talk to them.
Look for a clean looking busy place with nice people running it.
Ask a few questions and ask about their qualifications and training.
Not all places have trained tech/mechanics.
If they do not find a place that does.
Even all dealers do not have all trained techs/mechanics.
MT

[CENA]

Ok, I will change the plugs and wires. Might be a couple of days. I will let you know if anything changes. Right now the light is off. When I change the plugs and wires, it may be quite sometime before the light comes back on, if it even does. Like I said, it only has happened when pulling my snowmobile trailer. And the season is done now. Either way, I will let you know. Thank you all for your help!!!

[wafrederick]

Another tip,stay away from cheap plug wires from AutoZone and Advanced.Cheap plug wires are not the way to go and you will replace them a lot.

[CENA]

What plug wires do you recommend? I was going to get the Bosch wires from Autozone.

[MT-2500]

If you love your Tahoe do not let them push that cheap Bosch stuff off on to you.

AC Delco is the only way to go.
Wires or cap and rotor or spark plugs.
MT

[CENA]

Alright everyone, I never got around to changing the plugs and wires. I decided to wait, because I' am not so sure on this. It seemed like the only time the light came on was shortly after putting gas in. Well, yesterday it happened after about a month. Right after putting gas in! I always turn the gas cap till it clicks a few times. It started chugging and then when I gave it gas it seemed to slowly go away. Got home, took off the gas cap, put it back on and the light went off. Any ideas here???

[MT-2500]

Does the check engine light blink or stay on steady.
I would recheck and see if it is th same code.
Do you top off the tank or fill it as full as you can get it?
Do you fill it up with engine running or engine off?
Any gas smell when it does it?

[CENA]

No gas smell when fueling, no I do not top it off or fill with engine running. Light will blink a few times and then stay on. Engine will chug until I give it gas and then it will run normal.

[MT-2500]

If it only does it when you fill up the tank.
Could be something o the evaporative emissions.

[glenncof]

Loose gas cap will throw a code, but not P306.

Plugs ... use only the AC Delco spec'd. Might as well do them AFTER diagnosis, since your near 100K IF they had not been done. I checked the gap on mine at 100K and they were almost in spec. Amazing. BTW, throwing parts at the problem only make diagnosis harder and rarely fixes thing.

You could pull plug 6 and inspect.

You got the first major weakness; intake manifold leaks...now out of the way. Another is the CSFI (1996-1998, Central Sequentail Fuel Injection). I had start-up problems and used Techron injector cleaner a lot, never throwing codes but a loud bang at start-up.

Wires ... factory one I replace at about 130K and slight signs of arcing. You could do the plugs and skip the wires for now. Just carefully examine wire 6. I have been known to go to a tuneup shop and grab an old wire to replace suspect. I mention since the poppet (?) stick sometimes.