How much of a difference?

[redrocket5.0]

My car is very choppy, just figured it was due to the blower. I need to get it tuned. But I scanned for the light a couple weeks ago, said bank 2 sensor 2 slow responce/ no signal. Cleared it, seemed to run ok. Light came back on after 2 weeks or so, scanned it again, same code. So I pick up new sensors and put it in the air. Well, whoever put in Xpipe did a shitty job, first hole for O2 sensor was too close to bellhousing so they just stuck it into the sensor 2 location, and said the hell with the downstream sensor. Will I see a big difference once I put new O2 bung and sensor in? Car is currently getting 14-15mpg. I think it should be higher.

[Andy@PrimeTuning]

Yep the front 02 sensor needs to be heated both internally and by the exhaust. Moving it more forward to where it is supposed to be will make it work much more effectively.

Depending on your mods and how your tune is setup, it could make a big improvement to the way the car drives. Or it might not change a thing if the tune is wrong anyway.