o2 sensor

[jrdn223]

How bad would a faulty o2 sensor affect my gas mileage. it seems like i'm just throwin money in the tank of late. also when i start my car for the first time in the mornin it revs a couple times (flashing the check engine light) and then stalls unless i give it a good bit of gas. is this the o2 sensor malfunctioning?

[MR 325]

Gas mileage could be a 02 sensor problerm for sure.

With a faulty sensor, the car is reading a constant lean, therefore dumping gas in.

[Dominick]

i had the same problem, then i replaced the o2 sensor, fuel filter, cap & rotor and im getting good mileage again. Basic tune up should help a lot.

For the o2 sensor i used the mustang 5.0 sensor, saves about $100. Search cuz i dont have the links to more info on it.

Good luck

[jrdn223]

yea i'd really like to know the cheapest way to replace the o2 sensor. i'll do a search but if anyone else has any input it would be greatly appreciated.

[nando]

I got my O2 off ebay for $65, took me about 5 minutes to put it in with a burning hot exaust manifold.

[Digitalwave]

I got my O2 off ebay for $65, took me about 5 minutes to put it in with a burning hot exaust manifold.

Same here. I got an OEM Bosch for $65. Very easy to install.

[Dominick]

damn i wish i had saw that earlier, no cutting/splicing wires

[thejimlab]

You can get an 02 sensor from any 87-92 Mustang 5.0liter from autozone for about $40. All you have to do change the connector.

[Den]

You can get an 02 sensor from any 87-92 Mustang 5.0liter from autozone for about $40. All you have to do change the connector.

I did this on my E28. Splicing is easy with butt connectors. Works fine.
Word is that all the Bosch O2 tips are the same; only the wire lengths + connectors differ.

That Mustang sensor has 3 wires though.
Late E30's use a 4-wire sensor.
Anyone know a good $40 4-wire candidate?

[UDM Motorsport]

so i have a 87 325is.

I just ordered an O2 sensor, didnt know what i have on the car.
The one i ordered is a bosch 4-wire O2 sensor (#558570504)
the application is for 325i, is thru 8/87.

i looked on my car and the factory one has 3 wires.

so can it still be used?

thanks
franklin

[robmespeedy]

You can get an 02 sensor from any 87-92 Mustang 5.0liter from autozone for about $40. All you have to do change the connector.

Hey i just bought an O2 for the mustang just like you said . It has three wires Black , white and white .
Can the 2 whites be connected either way ?

[Dominick]

it doesnt matter which white is connected to the other, just make sure you go black on black

[Den]

Yeah, the 2 white wire are just the heater loop. Black wire = signal.

[Brew]

Guys, the O2 sensor doesn't function until the car is warmed up.
:idea:

So... jrdn223, your cold start issue is most likely something else. Gas mileage can be a number of things including- O2 sensor, incorrect fuel pressure, misfire from bad coil, cap, rotor, plugs, wires, etc. I'd say the first thing to do would be to check the condition of you spark plugs, then do some electrical tests on the other things I mentioned.

[robmespeedy]

Does Anybody need a Brand New O2 sensor , let me know
i can get brand new motorcraft O2 sensor , 3 wire

PM me . $30 shipped