Hey all just bought a 99 S80 and sometimes when accelerating the "check engine" light flashes and i loose power. Now I have already replaced the faulty Coli Packs and when I took it to autozone they said it was a fuel to air mixture code but didn't write down the code before he unplugged it. Could this be one of the O2 Sensors? The emmisions light message is on so thats my next guess. Thanks in advance for the help!!

 

I'd check/clean the mass airflow sensor first.

Would be good to have the actual code since if it is something like that or 02 sensor(s), it may indicate which one is causing the code.

 

Thanks Falasi,
I hate to sound ignorant but would that be where the air filter is too? If not where would it be?

 

Yes - the MAF is attached to the airbox - 2 torx screws if memory serves.
It has wires to it - not vacum tubes.
A lifetime supply spray can of MAF cleaner is about 6$ at the autoparts store.

 

Found it and cleaned it. Found a trick online to put it in a bag of alcohol and shake it and then let it dry completely. No go so I think my next move is O2 sensors. Btw where can I get a bottle of Power Steering fluid? I can't find any yet.

 

only go to volvo to get the steering fluid, i went to an advanced auto parts, they told me what they thought was best to use, i used it & i just had to buy a new power steering rack, so yea i would recommend just going to volvo its like $25

 

I went to my local dealer yesterday and they filled it for free! I had to ask like 3 times to make sure I heard right lol. But since they are the only one in the area they most likely did it so I'll return.

 

i found out it is infact the front O2 sensors. Gonna get them replaced and see what happens!

 

If the O2 sensors are not to hard to reach, keep in mind most auto parts places loan the O2 socket for free. Last O2 I changed was on a different car but other than crawling under it was as easy as changing a spark plug with the proper socket. Took more time to get it up on ramps and jackstands than actually changing the sensor. I have not looked for the ones on the S80 yet.

 

If you are near a Harbor Frieght Tools, they have the O2 sockets for not too much. I think maybe around $5. There are two different types I have seen, one is a deep socket with a slot on the side, thise work good but I have found that they tend to really bend the wire a lot on the sensor as they should be a little bit longer to avoid that. The other one is like an off-set wrench. I have not tried using this one yet but seems it would be better on the sensor it is like a box wrench the the ratchet attaches to the side of it so the sensor can go all the way through without having to worry about bending the wire.

 

Personally I'd be doing a lot more troubleshooting before replacing the O2's. Its sounds more like a vac\boost leak and possible overboost. Most often if you have a vac leak it will throw a mixture code, and depending on where the leak it, it may cause an overboost condition too. What is the exact code # you got?

If the O2 sensors are dead the motor will just stay in open loop, you wont have a "sudden" drop in the powerband as its pulling just because O2 sensors have a problem.

 

A 1999 Volvo S80, details please...