Hi there , I have an 05 Mazda B3000 3.0L
I went on a road trip from Toronto Ontario across the north eastern United states and across New Brunswick and Nova Scotia.
this problem presented itself going up the very steep roads in those areas.. keeping the throttle just above 3200 rpm up a steep incline for about 15 seconds or so I would get a flashing check engine light and a huge drop in power. It also does this on level roads if you give it 3/4 or full throttle accelerating hard down the highway.
I took it to a mechanic in Nova Scotia checked the codes and came up with a cyl #4 misfire.. so they put new plug wires in... no real change..

When I arrived back home I checked the compression. all are in and around 160 psi ..
So I installed new Motorcraft plugs, motorcraft ignition coil and a fuel filter, the truck runs better with more power all around . but still has that flashing check light during a foot to the floor acceleration run.
I used a buddy's code reader and got a P0304 code.

I do not know what else to do

Please help me

 

P0304 is cam position sensor. It can cause the symptoms you described. They are about 20 bucks....


I'm an idiot p304 is a cylinder misfire not cam. I was thinking p0340. Cylinder 4 has an issue... first thing I would check is that the spark plug boot is seated properly. If compression is good it's a spark or fuel issue on cylinder 4

 

The spark plug boots are definitely seated properly .
how would i go about diagnosing a possible fuel issue?

 

You did a compression test
"all were about 160psi"

What was #4?

Compression test is not really about the numbers, it about the comparison of the numbers, i.e. if 5 cylinders were 160-165 and #4 was 155 then that might be an issue.

First swap spark plugs 4 and 5, to see if you got a bad plug, new plugs mean they have never been tested, not "they all work"

Does it miss at idle?
If so open air cleaner, pull out filter
Get a can of Quick Start(ether)
While engine is idling, and misfiring, spray some into the engine
RPMs will go up in general but listen for it to smooth out, no misfire
You are adding fuel manually, so if misfire goes away I would look at #4 fuel injector

You could try running a can of Seafoam, or similar injector cleaner in the gas tank first.