of the Y-pipe on the passenger side i already replaced the oxygen sensor on the drivers sider but which one is on the pass. side anyone know the vehicle is 1988 astro van 4.3 litre motor. Don,

 

It may have two O2 sensors. Does it look like an O2 sensor?

 

no it don't joe looks diffrent then the left side one. which is the oxygen sensor was in my chiltons book but cant find anything in the haynes manual. Don,

 

GM only shows the one sensor on the LH side, and the knock sensor seems to be in that same spot from the picture.

Nothing shown on the RH side. What does it look like? It's in the actual pipe itself? Maybe someone added something aftermarket?

The only thing I can think of is an exhaust temperature sensor.

Post a picture of what it is Don and maybe someone will recognize it. Otherwise, give the dealer a call and see if they can give you a hand.

This truck gets more hokey by the day. .

 

Joe i'm just replacing parts now so i know the history of it. Don,

 

Don,

It does not pay to replace parts that aren't bad or to do so if you are going to sell the truck. Think about if the truck is worth it to keep and if so, then attack the various problems it has and work out a plan of how to do it. Otherwise, it will cost you more to fix this truck than to buy one in much better shape. My personal belief is the truck you are starting with has had too many hands in it, and it will likely cost you a lot of money to make it right again. You could put your money to a better vehicle in my belief.

If you are thinking about getting rid of the truck, sell it AS IS or just do the basics to get it in running shape. Even so, doing more than the simple stuff will soak you for a lot of money.

 

Joe it does run and underneath the truck its very CLEAN i'm keeping it for now had to many experiences buying used vehicles all i need to do is buy amore expensive vehicle and have the same problems with it. Don,

 

Don,

Again, your truck, your choice . Sounds too problem ridden to me to be worth fixing, but that's me . Since you are keeping it, once again, I recommend you purchase the factory manual to guide you in your repairs and work. It is the best investment you should make before touching anything on the truck as it will provide you with answers to many of your questions.

That being said, what does this mystery sensor look like?

Can you post a picture of it here?

 

joe the sensor looks like the one on the left also in the haynes manual it says early models had two of them. Don,

 

Don,

If it looks like an O2 sensor, take it out and bring it to the parts store with you for a replacement. The counter person should able to figure out what is is.