2004 V70 Stalling When Slowing Down.. HELP!!
 

Hello all! I’m new to this sub and am hoping I could get some help. I have a 2004 Volvo v70 that I bought in april, it has about 140,000 miles on it now. about two weeks ago the check engine light turned on; that day I changed the spark plugs + coils and the light turned off. The following day I was driving on the highway going about 75 MPH.. when I went to a complete stop my car stalled, then all lights on my dash turned on, then off leaving only my oil light on. It started back up after stalling and since I was two hours away from home, I had no choice to drive back. It stalled twice after getting off the freeway when I was slowing down or coming to a complete stop. I checked my fuel pressure and it is at 50-60psi so I now no longer think it is the fuel filter or fuel pump. Not quite sure what to do now and it will run but I am now afraid to drive it.

Your first step should be to use an appropriate scan tool - plug in and see what codes are stored. Then follow a reasonable diagnostic process (not random replacement of parts and preferably not guess and check either - both get very expensive and frustrating) to figure out whats wrong.

For stalling when idling you could look at obvious things - like an intake air leak - you didn't specify turbo or non-turbo but turbo cars have many places they can suck in un-metered air - that can easily cause stalling. With air leaks you usually get fuel trim codes - those will be discovered when you scan the car.

I have scanned it, and got the code P0301, which is a cylinder one mis fire. Which could be multiple things.. we have checked all the possibilities for fuel problems and I have now cleaned the throttle body. It was sticky before cleaned. After cleaning I drove it up the street and the low engine power light turned on along with a rough idle. It is not a turbo and I am now stuck.

You should have codes stored again ( if you erased them last time) Scan it again, if it's #1 missfire - make sure you have compression, make sure the spark plugs are in good condition (when were they replaced?) and swap #1 coil to another cylinder. Clear codes, drive car - same problem? Scan car, has missfire moved? if so replace bad coil, if not -