Hey all, Im new to the site so please bear with me. I have an automatic 2001 Volvo s40 and when I go to start it up it cranks for a while before the engine turns over, sometimes giving the gas pedal a couple pumps helps. If its been running for a bit it starts up just fine after a crank or two. Sometimes after it starts after sitting for a while it sounds like the engine is choking as it gets going. My "Check Engine" light had gone on and off for a bit and I have my buddy run his VagCOM through the engine and it said that an O2 censor was the issue throwing codes but he also told me that he thinks the started would be the issue. The battery in the car is old too, so I don't know if maybe that could be it as well? Also the light in my gear select went out so I cant see what gear I'm in at night, any ideas on both of these issues?? Thanks!

 

Long cranking before start is usually the fuel pressure regulator.



There are two O2 sensors, one before the cat convertor and one after. Usually the O2 trouble code is the one after the cat. The code will say something like "cat convertor below efficiency". Either replace the lower O2 sensor or get something like this:
Oxygen Sensor Spacer (CEL Boss)

The shifter light is expensive if purchased through the dealer. I replaced mine with one from the auto parts store that was close to the original wattage. You have to remove the plastic shifter surround in order to replace the bulb and it's still kind of hard to get to with big hands.

 

Awesome guys thank you so much. Where can i get a new fuel pressure regulator? And as far as the o2 sensors, what does it looks like and how far after the cat will i find it? Thanks again for all your help.

 

The FPR is quite expensive these days at $205.60 + shipping from IPD. I bought mine at the local Volvo dealer for $79 a couple years ago.
Fuel Pressure Regulator - S40 V40

The two O2 sensors are located very close to each other at the top and bottom of the cat convertor. Assuming you have the "cat convertor below efficiency" code then you want to replace the bottom one (downstream) or get the O2 spacer I posted above. I bought the O2 spacer when the trouble code kept returning even after a new O2 sensor. I'm not buying a new cat convertor. Ever.
Buy Bosch Premium Oxygen Sensor 16292 at Advance Auto Parts