Hi, So my 99 xc70 starts running really rough in the middle of going up this hill, loose power, flashing cel.

I check the code when i get home and get a p0304. So i replace the always failing ignition coils and all the plugs. But, that didn't do it. I still get the code a really rough engine.

What to check next??? Tks

Doug

 

1)Fuel Pressure
2)Fuel Flow
3)Injector Flow
4)Compression
5)Fuel Trims
6)Vacuum Leaks
7) MAF proper value

A code does not tell you what is wrong with the car it only tells you what the symtoms are, you must figure out what the issue is without throwing parts.