help.. 1997 vortec 5.7 p0302 code

hey guys.. this is getting kinda frustrating.. have a 1997 k1500 chevrolet 5.7 vortec.. i am having a code that keeps coming up .. the p0302 code and nothing else

here is what has been done.. new fuel filter... new fuel pump... new a/c delco.. cap and button.. a/c delco iridium plugs gapped at 60... wires are good... new egr valve... i have run seafoam through the gas tank.. i have run techron through the gas tank...

when the check engine light comes on, it does not blink.. comes on solid.. it might come on after 3 days prior to clearing the code or as soon as maybe 5 miles after clearing.. the so called miss is only noticable at idle.. and some very slight studdering and hesitation after lifting off brake at idle and going ... while running down the road it feels good

this little bitty is getting expensive to fix..lol

Check for vacuum leak(s) at the intake manifold gaskets.

Also, the spider injection system used on that truck are known to cause misfiring issues.

Good luck and keep us posted.

update:O( this is turning into a nightmare...

earlier today.. was thinking about the oil pressure being kinda low.. ran some seafoam through the brake booster line and was going to go back with conventional oil instaed of the synthetic after doing a engine clean...


well after doing all this.. i know have noticed a slight knock or rattle at startup.. and you can also blip the throttle slightly and hear a rattle on de-acceleration.. you can hear the rattle coming from the passenger side valve cover ... wondering now.. if i have a possible valve sping broken.. wrist-pin..etc.. this would i guess explain the p0302 code and possibly the low-oil pressure? we are going to take off the vavle cover tommarow.. maybe the seafoam got rid of some gunk that was slightly masking the sound?... any ideas on what this rattle might be?

Removing the valve cover and checking for broken parts is a good start.

You should still check for vacuum leaks and the injectors as previously recommended.

A compression test and/or leak-down test wouldn't be a bad idea at this time either.

How many miles on the engine?

126k .. not sure how to do a leak down test though

Google "cylinder leak-down test".

You can likely rent a tester.