Would you agree with me?

[3 Lions]

Hi guys,

 

So my dad's car (2012 Peugeot 208 1.2 VTI) keeps throwing up the engine management light at random times, he bought an OBD scanner to see what the code was (Q0240) and it's the same code every time he clears it but it keeps coming up at random times. In the book it says the code is related to a faulty oxygen sensor, the thing is though some time ago the catalytic converter developed a small crack that was welded. I'm just trying to figure out weather the weld on the cat has failed and is producing incorrect values or weather 1 of the two oxygen sensors is actually faulty. I'm pretty sure it's one of the oxygen sensors, would you agree with me? 

 

Thanks

[dalekphalm]

Literally impossible to tell just based on what you’ve said. 

 

I’d also recommend physically examining the weld to see if you can see a failure. 

[dizmo]

It's really cheap to just grab some JB Weld and go over the weld again. Do that. If it persists, it's one of the sensors.

[mr moose]

O2 sensors can be a pain in the arse to diagnose, so much so that some mechanics just throw them out and buy new because the faulting finding time costs more then the sensor.

 

I'd check the cat isn't clogged up and is working properly first (especially given its already been cracked once and re-welded), It wouldn't be the first time a dodgy cat has caused an o2 code to be thrown.

[Theguywhobea]

Don't O2 sensors cost like $12? Just replace them and see if that helps before messing with the catalytic converter.

[Ithanul]

2 hours ago, Theguywhobea said:

Don't O2 sensors cost like $12? Just replace them and see if that helps before messing with the catalytic converter.

Depends on the model of the vehicle and if upstream or downstream sensor.  My Frontier's O2 sensor cost me in range of 45 to 77 bucks.

In the case of some vehicles, some even have two upstream sensors, usually in annoying spots to get to.  So, depending on the cost of the sensors and how many, a good chunk of money can easily be eaten up by trying to replace them all.

 

Best route is to make sure it is not the cat like mr moose said.  A bad one can throw that fault code too.

[Jumper118]

considering its french, i think the best option is to take it to the scrap yard. probably written off. 

[3 Lions]

45 minutes ago, Jumper118 said:

considering its french

The 208 is a fantastic car sir

[Jumper118]

16 minutes ago, LinusTechTipsFanFromDarlo said:

The 208 is a fantastic car sir

hyes, it would make a lot of cans

[3 Lions]

1 minute ago, Jumper118 said:

hyes, it would make a lot of cans

Honestly it's a very nice car to drive, has lot's of low down torque and easily get's to 80 mph without breaking sweat. 

[BlueChinchillaEatingDorito]

<Insert Peugeot joke here>

[3 Lions]

4 minutes ago, BlueChinchillaEatingDorito said:

<Insert Peugeot joke here>

I admit Peugeot haven't had much success in the past but around 2012 when they did lots of re-branding their quality and reliability has improved drastically.