Running a 2005 s40 with 2.5T, 240k miles. I get an intermittent miss only at 1800-2000 rpm with about 20-40% load (moderate inclines) . I just changed the fuel pressure sensor suspecting that but still there. I plan on changing plugs next. Any suggestions ?

 

see if you can get the car to produce a DTC code by getting it to miss more frequently - that may tell you which cylinder(s) are missing. Also do you have a code reader that can monitor fuel trim real time? A lot of possibilities here - fuel delivery/pressure, spark (plugs/coil/wire harness), air metering (MAF, O2 sensor, intake/exhaust air leaks). If you do the plugs, inspect the connectors on the wire harness to the coils. Are the coils original?.

 

don't know the car's history so not sure if coils, wires, etc are original, but could be. I do know the plugs are at least 60,000 miles ago. The old code reader is not showing any codes nor were any showing up with vidas last time I was at the local independent Volvo shop. I don't have a reader to give realtime results.

the odd part is the miss is only at a certain load and in a very limited RPM range. give it more or less pedal and it is gone.

 

doesn't sound like the miss is that severe if there's no CEL. Plugs are due at 60K intervals, and depending on your engine code, you may be due for a timing belt at 240K miles (most are 10 year/120K miles except VIN codes with a 39 which is 15/150K). I'd inspect for vacuum and exhaust leaks which can lean out the mixture and inspect the connectors to the coils to see if there's anything cracked. Go with OEM plugs - more expensive doesn't always work better on Volvo turbos.