Exhaust problem, loss of power, higher fuel consumption?

Question

I have Mitsubishi Colt 1.3 (2001).
The problem started when I had my MOT. There was a gas leak (hole) at the front down pipe but the car otherwise ran fine (if you ignored the noise).

The garage I was doing the test at ordered a new part which wouldn't fit because apparently the
previous owner had cut a section out of the exhaust and welded on a catalytic converter. So
they had to create a section with the new part that would fit. They eventually did that and the
car passed its MOT.

The next day however, while I was accelerating on the motorway the car stopped
responding and started losing power at the point where I was struggling to maintain 40mph. After a couple of minutes the problem went away on its own.

The car will do this again almost every time I put my foot down while the engine runs at relatively low rpm. I tried putting the car on neutral and revving the engine; this will sometimes
clear the problem temporarily. I can hear a strange grinding noise which I think is coming from the direction of the catalytic converter. I have also noticed that fuel consumption has gone up.

I took the car back to the same garage to find out what was going on. They ran a diagnostic and found a few error codes (listed bellow). They cleared the codes and test drove the car. They ran the diagnostic once again and no error codes would come up. So they basically said to me they didn't know what was causing it and told me to come back when it does it again so they can investigate.

They charged me 35 pounds for half an hour labour and told me it could be 2 hours labour the next time (140 pounds), just to find out what's wrong, which I am not willing to pay. The car originally cost me 500 pounds and I've already spent 200 for the
exhaust which as far as I am concerned went into ruining the car.
Can anyone help me pinpoint the problem?

error codes:
3C01 (Speed Sensor)
3C02 (Knock Sensor)
3C04 (Barometric Pressure Sensor)
3C08 (Injector)

Answer 1

I don't think it is funny. Looking at your codes, you a one code not in common. It is the speed sensor code (ignition), think of what happens if you turn the ignition off. When it is turned off all the outer codes will happen.



The repair shop you went to is typical. They think you and the car are lying! After servicing your car they should just pull your codes for free. This does not cost anything.

One more thing if the convertor is loaded with rust, it maybe cooking the speed sensor.



Please let us know how you make out.

Answer 2

They did NOT do something MORE IMPORTANT that is QUITE CHEAP! They did NOT clean the THROTTLE BODY and the IDLE AIR CONTROL VALVE! ALL AIR that enters your engine comes through the THROTTLE BODY< and the computer adds MORE air as required from O2 sensor signals with the IAC valve! BAD OIL will make SLUDGE that glues these things TOGETHER and STOP WORKING !I use AMSOIL POWER FOAM to do this simple job and follow up with GUMOUT spray! I also run them BOTH through the PCV VALVE to dislodge hidden SOOT and CARBON baking into the INTAKES and seals, PISTON TOPS and RINGS! A STICKING IAC valve will CLOG up converters and OVERLOAD O2 sensors as well! It is the MOST overlooked part of ANY injection system! MODERN FUELS have LOTS of detergents and cleaners in them to keep the AIR CLEAN and to prevent INJECTOR CLOGS! It is the AIR side of things that need HANDS ON CLEANING as no additives will clean them UP! TRY IT and SEE what I MEAN! ALSO use DENSO IRIDIUM PLUGS or TWIN TIP plugs for MORE POWER and better economy and LOWER emissions! GOOD LUCK!! THEREFORE>>> Your foot only adds AIR to the engine FUEL is metered and INJECTED< and the IAC valve adds MORE air as required! To PUMP your foot only gets it some EXERCISE! There is NO FUEL PUMPING here at all, unlike on a CARBURETOR with an ACCELERATOR pump! The TPS is what tells the computer HOW FAR your foot is DEPRESSED and adds the FUEL! A DIRTIED UP IAC valve will RUIN your AIR/FUEL MIXTURE and cause CONVERTER DAMAGES! On most cars it comes into play mostly in CITY stop and go driving, but more sophisticated engines from EUROPE use it to add AIR at ALL SPEEDS!

Answer 3

haha