p300 code random misfire - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

steven2680 · 03-25-2015, 10:41 AM

What's up guy I have a problem with this code p300 I know that is a camaro forum but I have a 2003 chevy tahoe . The code p300 came up I chang spark plug, wires ,I change the plugs back in dec, I don't know what can it be i appreciate any help thanks

Jayrcr3 · 03-25-2015, 10:58 AM

Intake gasket, or vacuum leak after the MAF sensor would be where I would look first. P0300 indicates that the misfire is random, and not isolated to a particular cylinder. A bad plug, plug wire, or coil pack would be the same cylinder every time. For example A P0301 code would indicate a misfire on cylinder one.

steven2680 · 03-25-2015, 11:11 AM

Cool I just pick up the maf airflow my truck have 118,000 mile the wires was change last night thinking it was the problem but it wasn't the plug was change on December but I just pulled them out from the passenger side and they look White i did the driver side also and are brownish

Jayrcr3 · 03-25-2015, 11:29 AM

Sounds like the passenger bank is running lean.

steven2680 · 03-25-2015, 11:41 AM

I change the maf air flow and still doing the same thing ing

CamaroCracka · 03-25-2015, 02:06 PM

He said a vacuum leak past the MAF, not the MAF itself. You probably need to replace the intake gaskets if the whole bank is lean.

steven2680 · 03-25-2015, 02:18 PM

I check all vacuum lines and I haven't seen no leaks. I replace the intake manifold gasket about 5 years agocould the intake manifold gasket be broken already

CamaroCracka · 03-25-2015, 03:32 PM

If the leak were from a line, the problem would likely be seen on all cylinders. Since you say the plugs on one bank are white, the like culprit is the intake gasket on that side. You could try spraying starter fluid around the that side of the intake and see if the idle changes. If it does, three is a vacuum leak.

steven2680 · 03-25-2015, 04:03 PM

I already Spray carburetor cleaner around that area and I haven't seen nothing change

CamaroCracka · 03-25-2015, 10:39 PM

I have a similar problem on my truck but only cyl 1 n 6
Just replaced gaskets despite no change when spraying starting fluid
Running a scan on Fri
I'll let u know how it goes

steven2680 · 03-26-2015, 05:38 AM

Ok think bro since the truck have 118,000 mile I havent done nothing to it but a water pump woo I just order some parts and see which 1 is the part that making the truck misfire I will give a update when I find the problem

CamaroCracka · 03-27-2015, 03:33 PM

I put the gaskets on and I can no longer hear the brief whistle from inside the cab when I blip the throttle, but I still get some misfires on 1 & 6, but no longer enough to throw a code.

steven2680 · 03-27-2015, 06:09 PM

I did sea foam about 2 bottles it got a Lil better but now I have a misfire on cyl 7

CamaroCracka · 03-30-2015, 11:42 AM

There was oil on the intake runners. I think I will give that a shot.

03-25-2015, 10:41 AM	#1
steven2680 Drives: ss beast Join Date: Sep 2013 Location: elizabeth nj Posts: 259	p300 code random misfire What's up guy I have a problem with this code p300 I know that is a camaro forum but I have a 2003 chevy tahoe . The code p300 came up I chang spark plug, wires ,I change the plugs back in dec, I don't know what can it be i appreciate any help thanks

03-25-2015, 10:58 AM	#2
Jayrcr3 Drives: 2011 IOM 2SS/RS Join Date: Dec 2010 Location: Chatham, Illinois Posts: 756	Intake gasket, or vacuum leak after the MAF sensor would be where I would look first. P0300 indicates that the misfire is random, and not isolated to a particular cylinder. A bad plug, plug wire, or coil pack would be the same cylinder every time. For example A P0301 code would indicate a misfire on cylinder one. __________________ American Racing 1 7/8" Headers and Hi-Flow Cats, CAI cold air intake, Flowmaster AT exhaust, Vengeance Racing Stage 2 cam, VMax ported throttle body, TEA valve springs and titanium retainers, Trick Flow hardened pushrods, 180* T-stat, Comp Trunion kit, ZL1 Fuel Pump, ADM Fuel Pump Control Module, 20% window tint, Whipple Supercharger. Tuned by Mike Norris Motorsports. 656rwhp/584rwtq @10 PSI.

03-25-2015, 11:29 AM	#4
Jayrcr3 Drives: 2011 IOM 2SS/RS Join Date: Dec 2010 Location: Chatham, Illinois Posts: 756	Sounds like the passenger bank is running lean. __________________ American Racing 1 7/8" Headers and Hi-Flow Cats, CAI cold air intake, Flowmaster AT exhaust, Vengeance Racing Stage 2 cam, VMax ported throttle body, TEA valve springs and titanium retainers, Trick Flow hardened pushrods, 180* T-stat, Comp Trunion kit, ZL1 Fuel Pump, ADM Fuel Pump Control Module, 20% window tint, Whipple Supercharger. Tuned by Mike Norris Motorsports. 656rwhp/584rwtq @10 PSI.

03-25-2015, 02:06 PM	#6
CamaroCracka Drives: 2010 Turbo LS3 Join Date: Dec 2009 Location: Palm Bay, FL Posts: 2,736	He said a vacuum leak past the MAF, not the MAF itself. You probably need to replace the intake gaskets if the whole bank is lean. __________________ 2010 SS - On3 kit with downpipe cutout, CTR 78/80, CompCam 239/251 620/632 122+4, E85, Z28 suspension and ZL1 diff with Outlaw axles. Gen6 ZL1/1LE brakes. 2011 Vert - 416/w 230/236 .612/.602 115lsa, 1LE suspension w/32mm rear bar. Z28 diff. ZL1 brakes.

03-25-2015, 03:32 PM	#8
CamaroCracka Drives: 2010 Turbo LS3 Join Date: Dec 2009 Location: Palm Bay, FL Posts: 2,736	If the leak were from a line, the problem would likely be seen on all cylinders. Since you say the plugs on one bank are white, the like culprit is the intake gasket on that side. You could try spraying starter fluid around the that side of the intake and see if the idle changes. If it does, three is a vacuum leak. __________________ 2010 SS - On3 kit with downpipe cutout, CTR 78/80, CompCam 239/251 620/632 122+4, E85, Z28 suspension and ZL1 diff with Outlaw axles. Gen6 ZL1/1LE brakes. 2011 Vert - 416/w 230/236 .612/.602 115lsa, 1LE suspension w/32mm rear bar. Z28 diff. ZL1 brakes.

03-25-2015, 11:11 AM	#3
steven2680 Drives: ss beast Join Date: Sep 2013 Location: elizabeth nj Posts: 259	Cool I just pick up the maf airflow my truck have 118,000 mile the wires was change last night thinking it was the problem but it wasn't the plug was change on December but I just pulled them out from the passenger side and they look White i did the driver side also and are brownish

03-25-2015, 11:41 AM	#5
steven2680 Drives: ss beast Join Date: Sep 2013 Location: elizabeth nj Posts: 259	I change the maf air flow and still doing the same thing ing

03-25-2015, 02:18 PM	#7
steven2680 Drives: ss beast Join Date: Sep 2013 Location: elizabeth nj Posts: 259	I check all vacuum lines and I haven't seen no leaks. I replace the intake manifold gasket about 5 years agocould the intake manifold gasket be broken already

03-25-2015, 04:03 PM	#9
steven2680 Drives: ss beast Join Date: Sep 2013 Location: elizabeth nj Posts: 259	I already Spray carburetor cleaner around that area and I haven't seen nothing change

03-25-2015, 10:39 PM	#10
CamaroCracka Drives: 2010 Turbo LS3 Join Date: Dec 2009 Location: Palm Bay, FL Posts: 2,736	I have a similar problem on my truck but only cyl 1 n 6 Just replaced gaskets despite no change when spraying starting fluid Running a scan on Fri I'll let u know how it goes __________________ 2010 SS - On3 kit with downpipe cutout, CTR 78/80, CompCam 239/251 620/632 122+4, E85, Z28 suspension and ZL1 diff with Outlaw axles. Gen6 ZL1/1LE brakes. 2011 Vert - 416/w 230/236 .612/.602 115lsa, 1LE suspension w/32mm rear bar. Z28 diff. ZL1 brakes.

03-26-2015, 05:38 AM	#11
steven2680 Drives: ss beast Join Date: Sep 2013 Location: elizabeth nj Posts: 259	Ok think bro since the truck have 118,000 mile I havent done nothing to it but a water pump woo I just order some parts and see which 1 is the part that making the truck misfire I will give a update when I find the problem

03-27-2015, 03:33 PM	#12
CamaroCracka Drives: 2010 Turbo LS3 Join Date: Dec 2009 Location: Palm Bay, FL Posts: 2,736	I put the gaskets on and I can no longer hear the brief whistle from inside the cab when I blip the throttle, but I still get some misfires on 1 & 6, but no longer enough to throw a code. __________________ 2010 SS - On3 kit with downpipe cutout, CTR 78/80, CompCam 239/251 620/632 122+4, E85, Z28 suspension and ZL1 diff with Outlaw axles. Gen6 ZL1/1LE brakes. 2011 Vert - 416/w 230/236 .612/.602 115lsa, 1LE suspension w/32mm rear bar. Z28 diff. ZL1 brakes.

03-27-2015, 06:09 PM	#13
steven2680 Drives: ss beast Join Date: Sep 2013 Location: elizabeth nj Posts: 259	I did sea foam about 2 bottles it got a Lil better but now I have a misfire on cyl 7

03-30-2015, 11:42 AM	#14
CamaroCracka Drives: 2010 Turbo LS3 Join Date: Dec 2009 Location: Palm Bay, FL Posts: 2,736	There was oil on the intake runners. I think I will give that a shot. __________________ 2010 SS - On3 kit with downpipe cutout, CTR 78/80, CompCam 239/251 620/632 122+4, E85, Z28 suspension and ZL1 diff with Outlaw axles. Gen6 ZL1/1LE brakes. 2011 Vert - 416/w 230/236 .612/.602 115lsa, 1LE suspension w/32mm rear bar. Z28 diff. ZL1 brakes.