Bosch 16121 Premium Original Equipment Oxygen Sensor - Compatible With Select Audi A4

Replaced both O2 sensors on my VW Golf after getting DTC for O2 sensor prob. Plug n play pretty much with the right tools. Be sure to use a small O2 sensor socket for the sensor on the catalytic converter as the large O2 sensor socket has no room to fit. Although DTC for O2 sensor gone now, started getting P0422 cat converter code. Probably not the fault of the new sensors...

When I saw my check engine light come on I was pretty scared because thats always expensive!I took it in to get the error coded read and walked out with 3! Anyway, I was hesitant to fix the car myself as I had never changed an O2 sensor but it worked out great. It was a perfect fit. I didnt have to cut or splice wires. Anyone with a 7/8 wrench, a phillips screw driver, and jack can change this part. I was quoted almost $800 to fix my car and I did it myself for under $200 and got new break pads!

Good quality and works with a golf mk4

Plugged in, no problems and works. 2003 Volkswagen golf gti with a 1.8 turbo. This was the downstream sensor that was in the catalytic converter.

Bought a couple for my 2001 VW Jetta. The only complaint I have is that the O2 sensors are on top of the catalytic converter instead of the side like other German manufacturers (ex. BMW), but that's VW's fault, not Bosch's. Cleared the engine codes after installation and 200 miles later they still haven't returned. Ordering them online was much cheaper than the $200 per sensor the shops and dealer quoted me.I also bought an oxygen sensor offset puller (Powerbuilt 648691) because that was the only way I could get a socket around them. Even then, laying under my car made for a tough angle to apply enough torque to break them loose.

I bought this for my wife's 2003 1.8T (Mk4) Jetta. It is the downstream O2 sensor. It comes with anti-seize already applied to the threads and has a plastic cap to protect it. This is an OEM part and a perfect fit. I think the length might have been 1" difference if that.You will need an offset O2 sensor crow's foot style wrench or the Neiko tool sold on Amazon. I bought the Neiko tool and it did the job.

What can I say? Its fits just like factory. No problems. Will buy again if I need another. Definite quality product.

Seems to be as good as the OEM for my 2001 VW Jetta VR6. Plug is a match and works perfectly.

great its the oem downstream o2 sensor for vw mk4

Great product to replace my Back oxygen sensor on my 1.8T MKIV