lambda sensor fault? 1.6 petrol » Peugeot 307 forum » Peugeot Central

Posted: Sat 10 Sep, 2011 8:17 pm

Hi guys

I have an 02 plate 307, 1.6 16v petrol. She's not running right especially in the low rev range. Power is distinctly lacking, and can be hiccupy at times (great explanation I know). If I put my foot down the car pulls away nicely, but as soon as I take my foot off, the power starts to get iffy again. Fuel efficiency isn't quite what it was either. The dreaded anti-pollution fault message has come up too.

I have been told that my lambda sensor may be dodgey. I phoned a main Peugeot dealer for advice and part number, but they refused to give me the part number, and predictably told me only a peugeot dealer should fix that as its really sensitive and by the way, that'll be almost Â£200.

Can anybody tell me if a faulty lambda sensor might cause the engine to run they way it does, and if so, any suggestions on where to get a decent one and how easy it is to DIY?

Cheers
Mike

Posted: Sun 11 Sep, 2011 2:18 pm

Pre cat Lambda sensor is used by the engine ecu for exhaust gas oxygen level reference Â at steady rpm for fine tuning fuel/air mix for max economy so yes it could affect things at low rpm steady speed but is ignored when accelerating

Check out your pre cat lambda sensor output for fluctuating voltage between 0.1 to 0.9v flip floppjng every sec from max to min at warm idle rpm. All you need is a cheap multimeter

Even better of course is to plug in via EOBD and watch its trace as then you can see what's happening but a simple voltage output test would tell you whether the O2 sensor is working, whether it's sluggish, or whether it's stone dead

If you can read your car's fault codes then it will probably have spotted a really grim O2 sensor and flag a fault code for it as well as putting on your engine check light

Posted: Mon 12 Sep, 2011 9:40 pm

Hello, You can certainly test the pre cat lambda sensor by backprobing the multiplug connector with a cheap mulimeter as the above correspondent described, but a Fault Code Reader plugged into the diagnostic socket would reveal any fault codes, pending or stored, I saw one on Amazon yesterday for 16 pounds. However, if your wallet is a bit more flexible a good Scan Tool can show freeze frame and most important, live data, which shows both pre cat and post cat sensors switching in real time, it will also show if the Cat is performing correctly, the Autel Maxiscan is a best seller from <www talktomycar.co.uk> for around 60 pounds, these tools are an investment, you can use them on any car to interrogate OB11 specific codes and eliminate any expensive guesswork, these tools come with full instruction booklets, so anyone with half a brain can use them.
I hope this points you in the right direction and diverts you from the greedy clutches of the Peugeot Dealer, having read your predicament, I hate this sort of thing. I worked in several reputable independent garages over the years, these kind of people give everyone in the motor trade a bad name!!....Mike.

Posted: Mon 12 Sep, 2011 10:21 pm

Whoops, slight gaffe on my previous rant, please delete <specific codes> and substitute < generic codes> in the text ,sorry about any confusion........Mike.

Posted: Sat 24 Sep, 2011 6:37 pm

Hello.....if you have a look at E-Bay, you can find a suitable Lambda Sensor, and the socket with a slot which you need to fit it, for less than 50 quid. Its an easy 10 minute job too......well worth a try before giving money (Â£200!!) to the Peugeot Stealer. Pre cat and post cat are both the same item btw.
Hope this helps and saves you a few quid. I have changed a few of these (from e bay) for mates, and they are all working fine.....one of them 4 years ago.
Cheers.