How to change bank 1 HEGO sensor. Extended version:
1. disconnect spark plug wires from the coil pack. if your spark plugs are not original, it may be a good idea to mark which wire goes where
2. disconenct wiring to the coil pack and unscrew four bolts holding the coil pack in place. remove the coil pack
3. locate the HEGO sensor and put O2 w/ a 2" wobble joint and another extension on. if you plan on doing it w/o disconnecting the battery, be warned that mega fuse is located right where your hands will spend most of the time.
4. loosen HEGO sensor and remove it. if it does not budge... apply more force.
5. discover that the HEGO sensor thread got stripped possibly leaving chunks of the thread inside. curse... borrow freinds car and drive to Autozone. They sell spark plug thread chacers and repair kits. a chacer is just a bolt w/ three cut-outs like a tap. the repair kit includes actual tap and several inserts. Oh, be warned that the sales associates at autozone have no idea, so you have to find these by yourself. They sure as hell don't know that HEGO sensor thread matches spark plug thread, so don't bother asking about HEGO sensors.
6. get a chacer and go home full of hope
7. after an hour of trying, discover that due to clearance issues there is no way at all to re-thread the manifold in place. curse more...
8. count the things that might strip when you are dropping the manifold: two nuts and two studs integrated w/ a flange pressing y-pipe to the front manifold; two nuts pressing the y-pipe to the rear manifold (studs are screwed into the flange on the manifold); two nuts and expensive screws between y-pipe and the main cat (because even though you read DemonSVT's warning not to touch those when you install headers you want to optimize the y-pipe); gasket between the cat and cat-back
9.take an old HEGO sensor and wedge it in place of the stripped one. you are done till next weekend.
10. discover that car w/ exhaust leak is not really driveable (duh)
11. Monday moring call Bill and order manifold gasket, studs and nuts, also order all nuts around y-pipe, but not bolts/studs, hoping you will be ok.
12. reserve a rental for the next weekend because your wife and daughter have very important things that have to be done.
13. Friday night get a notification from DHL about the parts being shipped now (curse big time)
14. use rental to go to Chris and pick up most of the parts you need
15. come home and discover the package from Bill delivered (this is important, we will see why later)
16. start disassembling things. snap expensive bolts (what was I thinking, of course they had to snap), snap oneof the studs on the rear manifold curse excessively and with feeling... if you have a 20" extention, one wobble and deep 13mm socket, you can reach every stud from between the body and subframe (you have to find a good angle, but it works and you don't really need gear wrenches which you just got from Sears). there is no need to move the alternator out of the way. drive to autozone (you still have a rental) to get a wrench for the EGR pipe. you will save yourself a lot of effort if you know the size of the wrench you need (you can cheat: I know it's 1 1/16"). if you are not sure what size you need, don't take 1" and come back for bigger ones, get several wrenches in one go and return them later. they are around $18 each, but they will take them back w/o a fuss.
17. re-thread the manifold. use a lot of WD-40 to cact all the shavings in the chacer. you are done till next weekend
18. call Bill monday morning and present him w/ the butcher's bill
19. don't worry about the package from Bill because you know he ships on Friday overnight
20. discover that the package did not come
21. try to screw out the studs from the manifold... curse... curse more...
22. it's 90 degrees outside so take the manifold and walk around town to find any mechanic that may be willing to help you
23. come back home, cut off the studs and start drilling them out
24. discover that grade 8 studs are tough on drills
25. drill out the studs completely.
26. screw 6 studs in, put the gasket on and try to put the manifold on... alternator is in the way now. screw out all but the leftmost studs and put the gasket and the manifold on. now screw in the studs again. put the nuts on and tighten them from center out in a zig-zag pattern. you are done for the weekend
27. call Bill Monday to find out what happened w/ the package and re-order everything again. email and call Bill Tuesday to see why didn't the package go out Monday. repeat the same procedure on Wednesday.
28. take out remains of the y-pipe-to-cat bolts. use heat and BFH. use drill to take out whatever's left.
29. put everything together.
30. discover that nuts you got from Bill for manifold studs are not the ones you need -- use old nuts.
31. fire the car up. you are done
32. try to remember that if you leave your family w/o a car for an extended period of time, advertizing of $199 a month lease on a Mazda 6 really gets to you and your wife.
I hope you had a laugh. I certainly did not. I almost got a heat stroke when I was trying to get some local mechanic to drill out the bolts for me... last time I replaced HEGO sensors on my '96 it was so uneventful it was boring.
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