Could someone with hands on experience please explain the easiest way to access the first O2 sensor on the passenger side? Through the wheel well? Looks like a pain from underneath. My Haines manual is very vague. 1998 150 4x4 5.4
Thanks in advance for any replies.

 

Yes, through the wheel well. You might have to take out your inner fender liner...

 

That would probably help, but I replaced mine and the only thing I removed was the transmission dipstick tube. It made it a lot easier to reach the clip. Try putting a drop of WD-40 on the clip.

It took me less than 30 minutes to replace both front ones on my truck.
It is a pain though....

 

Thanks much for the info.