Hello: I am trying to locate the O2 sensor in my 1984 US 308QV. I assumed it was connected to the catalyctic but all I see is what looks like a 19mm bolt in a test bung. See Pic. Is this where the O2 sensor "used" to be or am I looking in the wrong place and this is a test port. Thx, Oleh Image Unavailable, Please Login
That looks like it. Your car will run much better without it. If you do want a new one, it is the O2 from a 99 Saab 16V Turbo. Buy the Bosch unit for that car. Much cheaper.
That is it, looks like someone removed it (obviously) LOL , anyway you may want to run down the rest of the Lamda system and see what is working and what is not. There should also be another smaller bung on the other end of the cat for your thermocoupler. Wade www.sportclassiccomp.com www.308qvregister.com
Actually what you are seeing is the pressure relief plug in case the cat get clogged. You are almost there, stay on that side and try to reach your hand on top of the cat and you will feel the wires with O2 sensor. It may even have a metal protective shield like mine that I just replaced. I have a 1985 US 308QV
I believe that is the "inspection port". Have a look on the other side of the cat at that same (inlet) end -- there should be a larger port for the O2 sensor: Image Unavailable, Please Login
you are right Steve, checked out a few cats I have laying around and two of the 3 have inspection (pressure relief ports) and one does not. Strange why one would and one would not. sorry to confuse Wade
That would be rather strange if they are all the "official" 308QV/328/TR cat PN 121385, but not all cats have such an inlet inspection port -- so, if the cat you mention without it is a different PN or manufacturer, that's maybe not unusual. On 121385, it is a just solid threaded plug so it really wouldn't have any "pressure relief" function -- just a place where you can look in to see if the catalyst matrix is physically OK or not, or where you can tap off a sample of "untreated" exhaust gas.
Thanks guys, When you had to replace yours, what was the best access, through the pass-side the wheel-well ? Did you need one of the O2 sensor special sockets or just a regular deep ? Oleh
I cannot remember if I took off the rear wheel or not. I do know that it was easy to get to and I did not need a special tool. This is a very easy DIY. Remember the Saab O2 sensor. Even the hookup is exactly the same.
Guys, is there just 1 cat on the US QVs? How does it run with a test pipe in there instead? Any difference? Thanks.
I replaced mine about years ago with a test pipe, it runs better is a bit louder but have gone through 2 O2 sensors since. Wade
Bought mine at a local parts store, original Bosch #13957, perfect fit including wires, no splicing necessary, $75. You don't have to remove wheel, just lay on your back if you can and slide under the car and reach in with open end wrench. Comes off like a spark plug with wire intact. Very easy
The 83 QV's had two cats. 84 and 85 had one. It runs fine with a test pipe and sounds pretty good too. It just is a eye and nose burning experience, more or less, depending on the tune. The Hyperflow cat is as good as a test pipe without the smell.
jlc308, The replacement does not seem to have the metal shield, did you re-use the old one ? The shield does not interfere with getting a socket or wrench on the thing ? Oleh
The metal shield is a separte part that has spring clips that go around the O2 sensor body so it can be removed before removing the O2 sensor.
Maybe this will be relevant; maybe not. I have a 1988 1/2 Mondial 3.2 and I just installed a Stebro w/ cat bypass (test pipe). The difference is amazing. Really; it feels like another 40 HP. I have been told the change shouldn't feel that dramatic, but it does. Maybe my cat was clogging up, but the difference is astounding.
