Change Of Lean Burn O2 Sensor 7A-Fe

[Konrad C]

Yesterday I changed my lean burn (O2) sensor from a breaking X reg car. I tested the sensor before paying £10. New air filter also installed just before the sensor swap.

The reason why I did all the changes, is that the new exhaust seemed more restrictive, plus the car struggled to meet the CO emissions until the last moment. I noticed that that the car was a bit flat before. Fuel consumption was also down, low 30s mpg.

Now it is a bit more lively. The throttle response is a lot better. Will need to do a few tanks to see any what my fuel consumption is now.

Out of interest I drove with Waqar and his car pulls well and is very smooth. My car was slower and noisier at speed. Not by much but enough. The gear ratios are exactly the same. My exhaust is getting much more quiet and on the motorway last week, the car performed nicely. Only the low medium speed needed the fixes. Will meet Waqar again soon to compare.

The O2 sensor that came out of the donor car had a lot more soot than mine. It also is unmarked unlike my Denso sensor. When I took my sensor out to swap, it was fairly clean with hardly any soot. I cleaned the replacement sensor and ran the car. Then checked it again and the sensor is still clean. I have have occasional EML's in the past (code 21), but the sensor it okay!

Tested resistance and got 1.8-1.9 ohms.

Overall the car is fine and need more time to bed in.

[Konrad C]

Update.

Car running very well so far. Pulls nicely and the exhaust is gradually getting more quiet.

I posted regarding the Techstream software and OBD to USB cable, because before the O2 sensor and air filter change, the car was gutless. Also it concerned me that the car switched from high CO, to very low in an instant during the MOT. It passed . No codes were stored in the ECU.

My mechanic who has Toyota software is on holiday, so I will ask him when he gets back.

As I said before, I suspect the O2 sensor may have been the cause, but the cheap £10 replacement seems to have fixed it.

[Konrad C]

Since the exhaust was replaced, I have had issues with the rear silencer and gasket.

I changed the silencer in November, as it was getting louder with lots of vibration and resonance. New one was fine for a while then the same issue!

I used some exhaust paste on the joint and it was more quiet for a while until I did some motorway driving. The noise came back with a vengeance.

Went back to Euro Car Parts and got a new crush gasket of a different design. This seems to be better than the other type.

The seal on the left was intalled in August and the new version. Both are the same part number but the design varies.

The new gasket has a slightly thick rim on this side...

But thinner this side, which helps make a better seal.

This gasket was failing to seal after 5 months use.

The affected joint.

I am not happy with the rear exhaust a Klarius brand, and thinking of changing it for Euroflo. The guy selling the Euroflo reckons that the Klarius is the better one, but for which car?

In the meantime, I will see how the gasket performs.

The leanburn sensor is working well. No EML so the one I replaced must have been faulty.

This should have added to my exhaust post.

[Konrad C]

Further to my previous reply regarding changing the rear exhaust, I have just done so with great results. The Euroflo system is superior React/Klarius system and cost slightly cheaper.

Details and photos of the parts and comparison are in the following link:

http://www.toyotaownersclub.com/forums/topic/162085-how-do-replacement-exhaust-catalytic-converters-perform/

Only Walker (the original makers of the exhaust) could make a better exhaust.