Anyone have an idea what is going on. I have an H3 2006 with 106k. Recently we had a P0128 code and changed the thermostat and coolant sensor. A p0300 code came up with this one. Since that time, the p0128 is now gone with the replacement of the above mentioned parts, but the 0300 is still there. We have done the following: changed spark plugs, replaced the crank case PCV hose (it was cracked) cleaned the maf & throttle body. Those didn't work, so we took it to the shop. They did an engine flush, due to sludge build up. Shop says it's not the coils or the head. After the flush, CEL light stayed off for about 3 days. Haven't taken it back there yet, wanted to see what you guys thought.

Light comes on & flashes when with car hits 1500rpms at 44 mph. You can feel the car bucking during this load. Light will stop flashing, but stay on once you speed up or slow down. No miss fires at other speeds or rpms.
Here is the freeze frame from the code:

P0300
fuel sys1 OL, fault
fuel sys2 n/a
calc load % 58.8
coolant 90
st ftrm1% 0.0
lt ftrm1% 0.0
Map 67
engine rpm 1478
vhe speed (km/h) 68
ign avd (deg) 25
iat (c) 22
maf (gm/sec) 21.640
abslt tps % 30.5

I have no idea what these things mean honestly. You're input is greatly apprecitiated.

 

So this issue from what I'm reading only does it around 44mph?

 

* spark plugs? brand, type
* maf, tb? did ya remove completely and clean wit maf cleaner & chemtool for tb?
* have ya changed out battery connectors?
* have ya run techron?
* have ya checked air filter?
* replaced all c.o.p?
* replaced all injectors?
* had battery load tested? age of battery?
* checked bolts for tightness?
Just some random thoughts? Try,n to help?
Chris

 

Chris, I have done all off your suggestions except the techron, coils, and fuel filters. We just replaced the vvt solenoid in hopes it was that. Coils will be next week. We are using a/c delco iridium plugs.

2wheelmonster, its always around the 45 mph and 1450-1670 rpms. Under All other driving conditions it does fine without misfire.

 

Possibly the cam or crank... Hey wait a minute there was a really good read about some screen deteriorating in something and then causing a stumbling and crap running. I hope someone will chime in with the exact name of this. It is if mem serves me near the front of engine passenger side closest water elbow. Or there about's. By the way it sounds like your check all your bases and I give ya allot of cu-doz for that.

Chris

 

Chris, I know exactly what screen your talking about, it's the vvt solenoid. Which we have changed now without luck. Headed into the shop Thursday evening. We have noticed that the car will clear the code itself if we have between 3/4 to 1/2 a tank of gas. Any time it's not in that range car will misfire when driving at approx 1500rpms. Hopefully it's something simple. Will post the answer once we get to the bottom of this.

 

Awesome. Hope its something straight forward.
Chris

 

Sounds like a "sticky" injector, you can buy the bottles of Techron fuel additive or I also recommend Lucas. Add to your tank(don't worry about adding extra), fillup with "top tier" fuel, run that down the highway a few times and all should clear out. GL

 

Check that you do not have an intake manifold leak. The fasteners are known to have come loose and the plastic intake manifolds have also cracked in the past.

P0300 can also come from an overlapping problem with the O2 sensor. Keep that in mind.

 

So, the engine light is going to drive me Insane. Changed the coils and lights staying on off course, but over the last few days the darn thing has gone away by itself. It always comes back, but us coming on much less frequently. I'm at the shop to drop the car off and of course the light cycles itself off 2 miles before we get here. May just take it on home and add some techron and check the intake like suggested. Thanks for all your responses so far!!