So my AFS-74 decided to stop working. I then attempted to revive it with a propane torch, didn't work. I was pressed for time so I got the stock 1-wire from the zone for $22. Got everything installed, fired it up and took off down the road. Within 1 mile the O2 started pinging perfectly and went into closed loop. It seemed like it was reacting a lot faster than the heated O2 when it was new.

Another thing that motivated the 1 wire was that I tested out the heating element. I hooked direct battery voltage to the O2. I was holding it and didn't feel a thing, just cold metal. After about 1 min I put it to my cheek, ahh, its luke warm....DumDaDum....its still luke warm. WTF!?!?! 500 degrees my butt

Oh, I am running Hedmen LTs and the bung is in the extender about 2 in from the collector.

 

Probably got a bad one from the get go.

I wired in my heated o2, also a AFS74 and havent had any bad exeperiences, unless you count going into closed loop faster and much more consisitent :-)

Watch your o2 crosscounts at a prolonged idle and/or when the temp drops.....................

later
Jeremy

 

I dont know if youll get a boatload of heat out of a heated NB O2. Its not like one of the controlled WB-O2s where it glows a nice orange at all times. Basically the heating element is there to dump some extra heat into the O2 to keep it warm and clean. Even after 100,000 miles the O2 is still nice and clean.

 

The 3wire for my TBI G20 gets hot enough in the header to get an accurate signal about 20 seconds even at idle after a COLD start. It goes into closed loop at 30 seconds and runs fine even when ice cold.

Your car can waste a substantial amount of gas in-town driving with short little trips and pollute alot more. The main reasons OEMs switched to them.

My old 1 wire in the header collector (full lenght headers) took about 1 mile to warm up as well. It worked fine as long as it was under load. In cooler weather when I stopped and idled it would cool enough to revert to open loop and give an O2 sensor code.

 

Yeah, I guess in the winter it will be a different story. I need to some how connect the 3 pin weather pack back onto the O2 so I can warranty it

 

Oh yes, u mentioned the zone and 02 which means Bosch. they have known grounding issues and also are not correctly calibrated to the GM fueling PID. Do a search and you will find lots more info on them as well.

If your going to run a 1 wire then get the Delco. If u shop around and try the turbo buick vendors or bulk Delco suppliers, u can get them for 20$ a piece :-) Or like 22$ a piece and 3 for $60.

later
Jeremy

 

I am going to warrenty that 3 wire I had. Although I need to get one of those weather packs so I don't have to hack them any more.

 

I got my connector new thru a CarQuest store.

U can walk a junkyard and yank them from 93-95 4.3 blazer/s10 and GMC siblings thou. Get u a free connector ot two.

There is a list somewhere posted here that has all the apps, also I believe if u search ebay for afs74 it will net u the listing as well.

later
Jeremy

 

I got mine at Pep Girlz..... in the "HELP" section.

 

If you look here at post #14 it has a list of applications that the AFS-74 was used on. Also has a some info on the BOSCH NB sensors.

https://www.thirdgen.org/techbb2/sho...hreadid=263519