took to shop for no fuel..replaced fuel pump and timing chain. ran good for 1000 miles. Started running rough at idle. When driving hesitates some and when stoping the idle drops to 600rpm them flucs from 500-800. changed plugs and wires. now throwing following codes P0300, P0308, P1316.

 

codes are:

P0300-misfire on multiple cyl.
p0308- misfire on cyl. 8
p1316- Excessive Emissions

I had the same. Replaced plugs wires and front o2's and put the old front o2's in the back and it helped out

 

The front and rear 02 sensors are different and should not be interchanged.

Jostice, what brand of plug and wire did you install? Have you checked the compression to see if #8 is low from a burned or stuck valve?

 

Bosch and Magna 8mm. Will check compression.

 

96 to 98 have interchangeable sensors.

but yes check for compression and check for proper fuel pressure and leak down. seen a few with bad injectors.