Rep Power: 0

Hi guys ive recently bought a honda civic 1.6 engine is a d16v1, it went in for a MOT and flew through most of the test .... then the emissions test came the tester tried 3 or 4 times to get it to pass but to no avail on the paperwork it said "exhaust lambda reading after 2nd fast idle ouside specified limits" he told me i need to change the lambda sensor and this car has 2 he got a price of £40 +vat per sensor so if both are needing replaced thats £80 +vat without cost for labour im a bit uncomfortable on paying possibly £100+ to get it fixed as im pretty sure i can fix this myself and ive found sensors on ebay ranging from 20 to 65 pounds i was gonna go for the £30 mark and do the labour myself but the tester said "its not something you can do on your back" which i find hard to belive the guy was quite nice nd helpful but from what ive seen its a pretty easy job hardest part removing the old sensor but im thinking its not as hard as hes trying to make me belive and at the end of the day its a business there to make money i just dont fancy being ripped of when it could be cheaper if i fix it myself as i think im pretty capable i did do everything else on the car including droplinks, backbox, camshaft sensor and many other things on this car and another car i own ive repaired engine mounts changed calipers discs pads basicly i like to fix my own things with being an engineer and i save alot of money i go to a garage and im paying 2x as much maybe more


Anyways what id like to know is, Can i do it myself? , Could it be anything other than a faulty sensor that will cause high lambda reading?

EDIT: Forgot to add the values from the test they are as follows

Natural Idle Test :
CO 0.003 (max limit 0.500) PASS

Fast Idle Test:
CO 0.261 (max 0.300) PASS
HC 37 (max 200) PASS
Lambda 1.657 (min 0.970 / max 1.030) FAIL

2nd Fast Idle Test:
CO 0.003 (max 0.300) PASS
HC 8 (max 200) PASS
Lambda 1.103 (min 0.970 / max 1.030) FAIL

Result: FAIL

 
Rep Power: 120

Could also be the catalytic converter itself.

With a proper infrared surface temperature reader, once the car is warmed up you should see a increase in temperature on the exit side of the converter. If it’s the same or colder, consider replacing that first before buying new sensors.

You will need the appropriate spanner and socket for the sensor and some penetrating oil, but yes you can take them out.

 
Rep Power: 0

Thanks for the reply, i did think about the cat unfortunatly i dont have a temp reader but ill keep that in mind.

I didnt think it was a hard job , well not as hard as the tester was making it out to be anyways, ive heard many people replace them and never heard anyone say it was very hard do DIY

 
Rep Power: 223

Spray penetrating fluid several times of the next few days to make it easier to remove the o2 sensors if you decide to change them. Also only use the original brand that came in the car, either Denso or ntk