I have been getting some bad gas milage and was wondering if replacing the catalytic converter would help. Just had tune up about 2 months ago and had the fuel filter changed in the process. Any ideas? It's a 91 v6 3.0 with 186,000. I also have engine light on. I'm thinking it could be the o2 sensor could that effect the milage?

 

could be, but I'd put more money on the O2 sensor


search how to check and see why the check engine light is on and see what's causing it

 

O2 sensor can affect mileage.

Some interesting info on O2 sensors to consider:
http://www.4x4wire.com/toyota/4Runner/tech/O2_Sensor/

 

Thanks guys. Gonna check it out.

 

Id check the CEL codes and go from there

 

What is cel? And how do I check it? Do I use the diagnostic scanner? And if so do u know what the best/ cheapest one to get? Don't know a while lot about this kind of stuff. Thanks again for all the help guys.

 

You can go you schucks or pretty much any local auto parts store and they should let you use one for free in their parking lot. CEL = Check engine light.

 

He doesn't have OBDII on a 91 truck, all you need is a paper clip to check codes with his truck. http://personal.utulsa.edu/~nathan-b...26diagnosi.pdf

 

I don't know what state you're in but if you can get away with a cheap cat I'd recommend replacing it with a new one. Recycle your old one and collect lots of cash. I was amazed how clogged the small holes were in my old 93 cat when I took it off at 115,000 miles. The new cat I put on was $60 and I got $140 for recycling my old one. Now if you live in CA you're not going to get away with a $60 cat.