99 Volvo s80 2.9 has a random misfire and high idle and is in limp mode will not rive above 2000 rpms

SOURCE: 2002 Saturn idling high then drops to normal

Your 2002 Saturn car has an electrical recall .I think its the ignition modual.Owners should contact saturn @ 1-800-553-6000, Prompt 3
Please remember to rate my help in this matter ! Thankyou!

SOURCE: rav4 99 P0303 ( random misfire) and P0300 and P0302

Had the same problem on my brothers Rav4. We changed the Plug wires and the problem is corrected. He had changed the plugs a couple of months ago. We had the code read at Advance Auto, it came up P0300 Random misfire. His old wires looked fine also.

SOURCE: rough idle. rpms drop. misfire.

try your coil packs they go over your sparks or do plugs first and see what happens do affordable first

SOURCE: 1999 Grand Am 3400 v6 misfire.

I was asking about the pushrods because I had this problem with one of these engines that had a bent push-rod. I robbed a push-rod out of an older 3100 and it was just a fraction of an inch longer which bottomed out the lifter. I figured it out by removing the valve cover and loosing the rockers when it was running and it smoothed out. I'm guessing you checked for vacuum leaks already. How about injection pulse on the number 6 cylinder when running. Another thing you could check is running compression. You said you checked compression but did you just check cranking compression or did you check running compression too.

SOURCE: volvo xc70 in limp mode 7 fault codes recorded d5

Possible problem with the alternator not putting out enough voltage. I had the same problem with my 2002 XC70, putting in a new alternator fixed it. I used a local mechanic who I found on the car talk web-site. Low Cost Volvo parts can be purchased at FCP Groton.