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Billy
Billy, Trainer/Master tech.
Category: UK Car
Satisfied Customers: 3498
Experience:  Trainer - master tech., SAE member
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Peugeot 207: Anti Pollution System Faulty !?!

Customer Question

errorIm getting and error message on my peugeot 207 1.4 16v petrol, anti-pollution system faulty. The engine is running rough on idle, and has very little power, nothing much happens when i put my foot down. Kinda like its in some sort of low power mode i.e. restricted.

It has dont 85,000miles, and is made in 2007.

This morning, i noticed that it was revving itself when dipping the clutch (not in gear) to 1500revs, and when releasing the clutch it dipped to 500 revs ! almost stalled.
Submitted: 4 years ago.
Category: UK Car
Expert:  Billy replied 4 years ago.

Billy :

Hello and thank you for using Just answer! I'm Billy and i will assist you with this. Feel free to ask if further info is needed.

Billy :

When the engine management system detects a fault within one or more of the components, it will do the following:

Billy :

- trigger the warning light to alert the driver

Billy :

- trigger the limp home mode (reduced performance) to prevent any further damage

Billy :

- register fault codes (relating to the fault itself), in the system memory.

Billy :

The best way to handle this, would be hooking a scan tool to the vehicle, and retrieve the fault codes. As the fault codes should identify the faulty component(S) or wiring to be further checked or replaced as necessary.

Billy :

The common fault on your vehicle causing this, would be dirt build up around the throttle body, causing the throttle to be uncalibrated.....thus the idle issues....

Billy :

However, the spark plugs, coils, oxygen sensors and other components can also cause the same thing.

Billy :

So you are advised to get the scan, retrieve the fault codes, and take it from there. Instead of checking /replacing parts at random.

Billy :

I can explain the fault codes, and tell you what and how to check if needed.

Billy :


Thank you for trusting JA and myself.......get back to me on this page, if follow up is needed.....Click on the ACCEPT button so i get credited for my work (positive feedback and bonuses appreciated)...

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JACUSTOMER-r41wcxrh- :

I didn't realise there was such thing as a limp mode, but that does certainly seem to be the case. Could you explain more to me about the limp home mode? How is it controlled/regulated? How does the car know there is a fault? Is there specifically anything that strongly indicates an anti-pollution fault? The error codes that have been registered are "throttle body" (as you have just stated) however, the throttle body was cleaned out, and the problem still exists. It is a little tempremental, it can be fine for a whole day, and give me jip the next. The car has been regularly serviced so spark plugs should be fine, just had new injectors put in as a misfires were occurring, the spray pattern was all to pot so that has been cured. Could you maybe give me a few things i could "try out" to fix? Which sensors could i test/clean? I think the coil pack would give a misfire, its definately firing on all 4, so its not coil pack.

Billy :

Hello,

Billy :

The engine control module triggers on the limp home mode (no longer takes info from the air mass meter and other sensors, but works on a pre programmed map in its memory), when a defect is detected. There are many ways to detect a defect, one of which would be getting a signal out of range ( like a sensor is supposed to give a voltage between 1 and 5 volts, and suddenly it gives 12 volts). When a fault is detected, a fault code relating to the fault is stored in system memory, so you can and should retrieve it, to get an idea on the fault origination and fix accordingly. Most sensors cannot be cleaned as these are electronic components, and the coil pack could still be faulty....giving a few sparks and then giving lower voltage sparks causing problems without misfiring.

Billy :

Having cleaned the throttle (it could still be faulty), and if you do not want to scan for now, and wish to try a few things (although retrieving the codes is recommended), i would check as following;

Billy :

- make sure you have tight and clean contacts on battery cables

Billy :

- make sure the battery ground cable (to chassis) has tight and clean contacts

Billy :

- make sure the engine ground cable (thick cable from chassis to engine) has clean and tight contacts

Billy :

- check the wiring connectors in engine bay....make sure you have none loose, disconnected or other.

Billy :

Other than that, you need to retrieve the codes and take it from there ( this would actually save you time and money by getting to the culprit in a faster way, without checking/replacing parts at random).

Billy :


Thank you for trusting JA and myself.......get back to me on this page, if follow up is needed.....Click on the ACCEPT button so i get credited for my work (positive feedback and bonuses appreciated)...

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