My mechanic removed this o2 sensor to clean it and I now have a replacement ,I know he got it out so it’s not seized but my question is how difficult is it get to and can I get it from under the car on some ramps ??

thanks again

 

Hi,

The upstream O2 Sensors are accessible from within the engine bay on the exhaust downpipes below the manifolds/headers with the connectors located on the frame near the front right engine bay fuse box. They are easy to replace and have good access.
The downstream O2 Sensors are accessible from under the car on the exhaust downpipes below the catalytic converters. The cables are routed round the back of the valve cover with the connectors right next to the valve cover by the firewall. These are a lot trickier to get to but not impossible.

I would suggest getting a 17mm off-set/crows-foot tool to install the sensor, this will make it easier to install and maybe in the future remove.
Also make sure you put some anti-seize on the threads and only on the threads.

 

Thanks for that,

in the uk we only have two sensors and they are the ones with the plugs near the firewall,

im familiar with all the wiring etc and can see the drivers side sensor but the one on the left appears to be more difficult to get to as it’s over to the side of the pipe ,wondered if that was accessible easier from underneath ,from the top it looks a total ******* 🤣

 

Are the X300 sensors 17mm rather than the common 22mm?

I have used a crowfoot for O2 duty on other cars, but more specifically a line/flare crowfoot rather than a standard/open one.

 

17mm yes ,gonna cut the wires off the old one and get it out with a spark plug socket then just work out some other way of tightening the new one down afterwards 👌🏻

 

Mine are definitely 17mm. The crows-foot would help if you can get one, as it's in a tight spot, you might be able to use an adjustable to lock it in though, I'd be careful about making sure you don't grip the metal cover, only the nut part of the sensor.
Hope it goes well

 

New sensor fitted fairly easily ,

the worst bit was laying u der the car with your face near the exhaust and knowing there’s two ton of car over your head ready to fall and kill you 🤣

luckily the old one was easy to remove and you can do it with a short 17mm open ended spanner and a hammer 👌🏻

car now runs perfectly with increased mpg by 25% at least and instant throttle response 😇

 

Good news, it must be nice to have a 25% mpg increase.
How did the cable routing go to the connector by the firewall? This always seems daunting at first.

 

The plugs are not yet connected back on the metal bracket because I had to remove both as my mechanic had marked the ‘correct’ plug with masking tape but turned out it wasn’t the correct plug for the knackered sensor,luckily I spotted it before connecting them wrongly lol

im going to remove the whole bracket and then clip the plugs back up then bolt the bracket back to the head 👌🏽

Not on,y has my usual fifteen mile round trip seen a vast mpg increase but no more stalling 👌🏽