95 v6 4runner losing power up hill, running rich

[4runninandgunnin]

I am about as mechanical as an orange in a tool box...I can change plugs, wires, oil, etc....but nothing too major (just an fyi).

The situation is this:

My 95 v6 4runner (which has 33x12.5 in tires, on 20 inch rims) manual tranny, seems to lose power quite a bit going up hills....more so than my previous 4runner with much smaller tires. This vehicle has 167K miles on it, after market dual exhaust (no leaks as far as I can tell), K and N air filter (which is recently cleaned), among other things. Ive heard that the K and N's play havok with o2 sensors anyway.


I plan on ditching these tires and rims ASAP, as they are fairly new and in good shape, but I want something more practical (the smaller tires may help). I know rigs lose power when large tires are put on, but this seems a bit excessive. I took a look and the o2 sensor, looks fairly old. Doesnt seem to have any vaccum tube leaks that I can tell, and its had a recent tune up (sept of last year, less than 3K miles ago)... Should I spent the 65 to 100 bones to buy and install a new o2 sensor, or should I look for something else with the vehicle?
O2 sensor seems fairly accessable, might be an issue and probably needs replaced...I just wanted to get any opinions...I really dont want to have to take it into a shop at this point in time....

Thanks for any input.

 

[Jeff4runner]

I can understand about your fear of shops. O2 sensor usually = 200$......

However, if you want to know if it is an o2 for sure, take it to autozone, and have them scan the codes. They are advertising free "check engine light", but it doesnt have to be on to send a low voltage/failing signal to the computer. But, Im not quite sure if the 95 has OBD2 system.

Otherwise, a local mechanic wouldn't charge too much (I think), just to check and give a professional opinion. We usually do it for free, and do car diagnostic with scan tool for 10$. The o2 sensor will run 80-100, and the labor, probably 100 also.

 

[4runninandgunnin]

Thanks for the response Jeff.

 

[4runninandgunnin]

I know this is an old thread...but thought I would update.

I took off the rims/tires...put on some stock wheels...while this helped, it still didnt do the trick. Took it to a buddy of mine, he checked it out...only running on 5 cylinders...one of the injectors was buggered....waited a few months to get some money so I could fix it...turns out, there were a few other injectors that were crapping out too...so, replaced the ones that needed it and cleaned the others that didnt. Seems to have helped. Just wanted to update.