Hi All,

My fiat punto sporting mk2 has had an engine warning light on for a good few months now and i'm running out of ideas what to try.

When i check the ecu i get codes for the power steering (read about the D4 connector and this has not sorted the problem but this isnt my main issue), P1135 pre cat lambda sensor and a MAP barometer pressure fault.

Over the past few months I have had two new Lambda sensors (pre and post cat) and a new cat due to an incident with a speed bump but the error message does not go away.

Im getting around 27 mpg whereas i used to get 34-36 so the car is running rich. The car does not idle well sometimes stalls on startup.

As part of my new cat i also has a new exhaust system and the inside of the pipe is black and i get black smoke when revving at standstill.

It all makes the car sound very sick when you write it down like this. Does anybody have any suggestions why the car could be running rich and idleing badly?

Cheers

Tony

have you changed the MAP sensor, as with that not workin, it wont know how much air is coming in and what ratio air:fuel,

I guess its acting like there is a strong air feed 100% of the time, and its adding alot of fuel, hence poor MPG and smokey exhaust

Since you got the fault codes - did you clear them?
as the car might not know a new sensor is on there - so its automatically staying in the overfueling mode?

clear the faults (make a note of the old faults too!) and see if they same fault codes come back

Ziggy

Ziggy122 said:

Since you got the fault codes - did you clear them?
as the car might not know a new sensor is on there - so its automatically staying in the overfueling mode?

clear the faults (make a note of the old faults too!) and see if they same fault codes come back

Ziggy

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Hi Ziggy thanx for the replies,

After changing the Lambda sensor a few weeks back i cleared the codes and it lasted about 300 miles before the light came back on still moaning about the sensor i had changed. Just because the ecu says there is a fault at P1135 it does not mean a faulty sensor does it just a wrong reading at that sensor? I will read the codes tomorrow and then its going to be research time on trying to fit the manifold pressure problem sigh

Tony

colinf1 said:

have you changed the MAP sensor, as with that not workin, it wont know how much air is coming in and what ratio air:fuel,

I guess its acting like there is a strong air feed 100% of the time, and its adding alot of fuel, hence poor MPG and smokey exhaust

Click to expand...

Hi Colin,

Do you know if this is a big job? might have to give it a try

Tony

i think it is part of the throttle body, not 100% sure of this, so if you take the TB off, and clean it all up with carb cleaner & tooth brush, reattach it and make sure all wires are reconnected, then see how it runs..

i have hjad the same problem with the engine warning light being on for over a year now and have taken the car everywhere including fiat,. they said there was nothing they could do and that they couldnt recognise a problem with the car.

sounds like a faulty sensor tbh

jip0 said:

sounds like a faulty sensor tbh

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A MAP sensor? i hope its not the Lambda sensors as I have changed these recently (last few weeks)

Hi All,

An update on this post. I cleared the codes from the engine and the next time it popped on the code was p1135 or lambda sensor. I cleared this and the car was fine until I went from 70-0 mph coming off the motorway and the car stalled thorwing the ecu on. This time the code is moaning about the MAP sensor and nothing else.

Sounds like a new MAP sensor I assume

Tony

Hi All,

An update to this post. I brought a second hand MAP sensor off ebay and fitted it last weekend. My mpg has now increased to ~36-40 mpg which is great.

However, my engine management light has come back on again after about 100 miles. This is the codes from my OBD-II reader at 300 miles

U1702 undefined code
p0130 02 Sensor Circuit Malfunction (Bank1 Sensor1)
p0105 (MAP) Manifold Absolute Pressure / (BARO) Barometric Pressure Sensor - Circuit Malfunction
p1135 undefined code
u1600 undefined code
u1700 (pd) undefined code
u1601 (pd) undefined code

Any body got any ideas on some help? I don't think the U codes are an issue but i cannot find what they mean on the internet.

Could the fact the errors are cicuit malfunctions show that the problem is infact not the sensors but a fuse? or maybe wiring?

Tony

Baro is the MAP sensor
O2 is lambda sensor, but could be a symptom of too much fuel

WhiteSei said:

Baro is the MAP sensor
O2 is lambda sensor, but could be a symptom of too much fuel

Click to expand...

you see i thought that the lambda sensor could be flagging due to the MAP sensor not working correctly and the fuel mixture being too rich. But now my mpg is sorted i thought that would also logically be sorted. Im confused more now one problem is solved but the still exist.

A mechanic did tell me it could be an air leak which i suppose would mess with the air/fuel mixture but this seems unlikely

Tony

Were the old codes deleted? Wipe the codes and then see what turns up.

WhiteSei said:

Were the old codes deleted? Wipe the codes and then see what turns up.

Click to expand...

I did clear them when i changed the sensor and it came back on again. After being told to clean my throttle body in another post I plan on doing this when im next at home to steal some tools.

for now im redexing it to see if that can clear the problem up a bit. Think there is a fiat specialist in Walsall I might take it to next time i'm home. Failing that might turn up to the italia meet and hope others have ideas

Tony

Check these out
http://shop.ebay.co.uk/?_from=R40&_...kw=punto+map+sensor&_sacat=See-All-Categories

WhiteSei said:

Check these out
http://shop.ebay.co.uk/?_from=R40&_trksid=p5197.m570.l1313&_nkw=punto+map+sensor&_sacat=See-All-Categories

Click to expand...

Hi whitesei

I brought one of those and fitted it last weekend that why my mpg is now at 40 rather than 28. puzzled however as to why my engine management light is still on showing a fault in the MAP sensor.

If i ahd brought a faulty second hand sensor it would not of affected my mpg surely? Im gonna wipe the codes out tonight before heading back from work and see what / if any codes come back

Tony

U1702 is undefined but is **** in your tb, thats the code i had and since i cleaned it its gone, stop wasting cash and do this simple 20 min clean up and see the results for yourself.

Sqwidge said:

U1702 is undefined but is **** in your tb, thats the code i had and since i cleaned it its gone, stop wasting cash and do this simple 20 min clean up and see the results for yourself.

Click to expand...

Will be doing this clean up next time I'm home so I can steal my dads torx set. Cant afford the 40 quid halfords want for a T and E set (not since i bought my new MAP sensor which was done before you gave me that handy little guide )

redex is currently flowing through the system cleaning my injectors anyways so that might move some of the crap too

£40? You know you can buy the individual bits right? I bought just what I needed and it was about £6 for the inverted star fitting.