Hi all,
Need advice pls. Own a Neon 2L 16V 2001 174 000 Kms.

Problem: Overfueling, black smoke emissions, low power, runs hot, heavy on fuel.
What have I done thus far: Reset computer box by disconnecting battery terminal. Car runs fine for a week and gets progressively worse.
Got error codes P1684,PO171 and P0140.
Removed semi-blocked CAT, fitted free flow system.
Was advised to replace fuel filter and clean injectors as a starting point.
Questions:
1. Error codes are for OBD11 type engine. Do I have this type?
2. I notice a valve at the end of the fuel line [metal pipe] that feeds the injectors.... is cleaning the injectors a DIY job.... does it run at a certain pressure which I need to re-instate after putting injectors back?
3.Want to replace the engine coolant, any manual or hints?
4. Will search this site for further info on faults codes and take from there.

Thanks.

 

Were the error codes before or after removing the CAT? In most areas it is illegal to remove the CAT also, this will cause ongoing error codes related to the downstream O2 sensor and will unlike older cars, affect the fuel mixture.

P:1684 = just means the battery was disconnected within the last 50 starts.
P:0140 = neither rich nor lean condition detected from the downstream O2 sensor.
(Probably a bad or disconnected O2 sensor)
P:0171 = Fuel injection system too lean.

Check the fuel pressure at the injector rail.
2001 model and newer 400 kPa ±34 kPa (58 psi ±5 psi.)

Many of the fuel additive injector cleaners do a good job but, should be used as ongoing maintenance once every few tanks of fuel.

 

Thank you for the response.
Only did my extensive [codes ] research after removing the CAT, so I do not know what the codes were before that. In South Africa, removing of the CAT is legal.

[ The problem is SA is that:
1. The agent's quote to replace the CAT is R8400-00 / $1000-00
2. To rectify the problem, the agent said to replace the LAMBDA sensors, CAT and
computer box.... totaling R14600-00 / $1800
3. R14600 is more than a quarter of the current value of the vehicle
4. 95% of the parts are at agents only, and compared to other cars, I seem to think
all the Dodge parts come gold plated.. the prices indicate that ]

So, I am in a process of elimination starting with the cheaper stuff first.
Is the 02 sensor and LAMBDA sensor the same thing?
Where are they situated, before and after the "CAT"?

 

Yes, a Lambda sensor and a O2 sensor are the same thing. There is an upstream one before the CAT, that controls the fuel mixture and a down stream one after the CAT, that has a far lesser effect on mixture but monitors the CAT function.
I would suggest replacing the upstream O2 I have read that it does not always trigger an engine code. The downstream O2 has no function once the CAT is removed but, the computer will give you error codes if it’s not in place and functioning. Check out ebay for a O2 sensor simulator, it’s designed to keep the computer happy by making it think it’s reading an actual O2 sensor (use on Downstream O2 only).

Do you know the reason he suggested replacing the computer??

Just A thought but the code P:0171 may be a bad upstream O2 sensor wrongly telling the computer it's running lean, causing the computer to over compensate with a rich mixture.

 

The agents seem to have an approach to quote "replacement on everything" that could be the reason for the fault.
Ok, thanks, have a very good idea of what needs to be done to try and resolve the problem. Will keep you posted.