O2 or Cat's on 2nd Gen Fronty 4L

I have a 2007 Fronty Nismo (4L) with 240 km. I've had her for about 10 months and love er to death. I changed the spark plugs in the spring. I was fearful they were original, but they were not. Had a coil-pack go this summer.

She has a 2 in lift with Wrangler A/T tires. I've not gotten great gas mileage since I've had her. I thought the plugs may improve that but they didn't. I get about 14 l/100km (16-17 mpg). I've attributed it to the tires and lift.

Over the last few months I've been getting a P0430 code. At first I could reset and it would come back after a week or two. Now it comes on within an hour of reset. I've scoured the forums and read everything from gas cap to new cats. I am suspecting its the cat but I don't want to replace that if its something like the o2 sensor.

So here is my question for you guys, can a P0430 code possibly point to the upstream O2 sensor? I read another post tonight that said that the O2 has its own code. I'd like to not replace both if not needed.

One last thing...over the last few weeks I've noticed a stronger exhaust smell. Tonight I pulled the truck into the garage (it had been sitting cold in the driveway). The wind was blowing into the garage so it blew the exhuast fumes in. It was pretty strong. Almost like a fuel/gasoline smell? My initial thought was if that left O2 sensor is bad its sending too rich of a fuel mixture through. But after reading the O2 has its own code, that made me think it really is the cat.

Lastly, if it is the cat, are there any opinions on the Walker 16468? There is one left on Amazon for $201 (Canadian) which seems like a good deal. If I should start with the O2, then should I get the tool? (the tall socket type or the short box head type?)


Ok, fire away!