HUGE power loss in 2nd gear at about 2300 rpm...

dhaberer · Post by **dhaberer** » 16 Jul 2010, 09:32

I have a 99 s80 t6, much to my dismay i have recently lost power, almost liuke its not catching. I had 3 coils replaced as well as all the plugs in october. Is it possible its time for the other three? Today I also replaced both the air and fuel filters>>>problem not solved. o2 sensors bad? if so how to tell whick ones are bad theyre not cheap so i dont want to do them all. Do notice armrest and cup holder area have been extra warm, catalytic converter?? someone please help

Post by **jblackburn** » 16 Jul 2010, 10:09

ONLY in 2nd gear? How does first gear respond if you get your foot into it?

Any check engine lights? You can have the car checked for codes by an Autozone/Advance Auto for free. Most of the time, an O2 sensor will throw a code if it is bad, as well turbo actuators, etc.

I would start with checking any intercooler hoses to see if one's come undone.

dhaberer · Post by **dhaberer** » 16 Jul 2010, 10:37

not just in 2nd gear but thats where it starts. No problem accelerating in first though. I just had diagnostic done a few days ago i get bank 1 sensor 1 for o2 sensors but i dont know which one that is! I also get the code for possinle coil misfire. I just dont wanna do the coils if its the o2 sensor and vise versa...any ideas?

Post by **jblackburn** » 16 Jul 2010, 11:09

A coil causing a misfire can trigger a code for an O2 sensor...when the plug doesn't fire, the gas doesn't get burned, so the sensor detects that as a too-rich condition.

I would look at the coils first to see if any are visibly cracked.

"Banks" are the terms for V-layout engines, which makes it confusing when applied to a straight-6; in this case, it would be the front O2 sensor for cylinders 1, 2, and 3 (passenger side).

dhaberer · Post by **dhaberer** » 16 Jul 2010, 11:48

no visible cracks...Do you think i should buy 1 new coil and and troubleshoot from there? pull and swap and see if i can detirmine a bad one? im obviously trying to get out of this as inexpensively as possible

Post by **jblackburn** » 16 Jul 2010, 12:22

Certainly worth a shot.

Reset ALL codes and then try it. The O2 will cut turbo response back if it detects something wrong (e.g. from a missing plug), so if it's mad AND the cylinders mad, that's why the response is lacking in 2nd when it tries to spool the turbos up hard.