Hello again.

 

My previouce problem with the car missfiring after have been parked hot summer days is not solved but now I have got more problems. https://www.briskoda.net/forums/topic/507467-p0420-missfire-12-htp/

 

 

The car is a Skoda Fabia 1.2 HTP (BME) 64hp 2007 with 383000km/238000 miles.

 

When the car is turned of the thottle body is buzzing for a couple of seconds every second minut. Last Monday when the car had been parked all weekend the battery was drained when I tried to get to work.

If I disconnect the contact to the throttle body it is quiet. 

 

This week I had an MOT-inspection. Everything was fine except for the CO-level at 2500 rpm. Maximum allowed level is 0,2 and at first the test said 0,4 and the MOT-technician said it use to drop after a little while but it only went higher and higher. We stopped testing at CO 0,8.

 

At idle the emissions was good:

CO 0,1 (max allowed 0,3)

HC 0 (max allowed 200)

Lambda 1,01 (0,97-1,03)

 

I have a new fault code, P2096 (post Catalyst fuel trim system bank 1 too lean).

 

 

Do I need to replace the throttle body or does anyone got another idea what is wrong with my little car?

 

   

 

Edited 7 December, 20241 yr by Naedhult

The throttle body on your car is connected only to the engine ECU. The engine ECU has no permanent connection to 12V, it is only powered when the ignition (contact) is on or engine is running.

So if it is making noise when the key is not in the ignition, there is a fault with the car's electrics, not the throttle body.

I think the ECU relay would be my first suspect, perhaps its contacts are sometimes welding themselves together. This relay is in position 12 of the relay carrier in the cabin.

 

The emissions problem may be a lambda sensor being too old, or possibly the catalytic converter. Or if you still have not checked cylinder compressions, then it may be an exhaust valve problem.

Edited 7 December, 20241 yr by Breezy_Pete

Had similar emissions problems on my 1.2. There was a slight leak from the middle section join on the exhaust and that was enough. Mechanic sealed it with black paste and it passed after that. He was surprised that such a slight leak made the affected the emissions. He only noticed it as there was some black soot there.

Alasdair 

Thank you both of you for replying.

 

I apologize for not answering earlier. I lost a bit of motivation when my problems became harder than I hoped and the weather was raining and cold.

 

Since last time I have bought a compression tester!

 

I got:

Cylinder 1: 12,6 bar

Cylinder 2: 13,1 bar

Cylinder 3: 13,2 bar

 

I have looked at the flexible pipe and it is probably still the original but I do not see any black soot and I started the engine, put a stick with a rag in the rear muffler, and put on dishwasher liquid with a brush on and around the flexible pipe but did not got an bubbles. 

 

Since previoce attempts to fix the missfires I had a extra first lambda sensor and intake manifold pressure sensor so I changed these again and fitted new spark plugs. I also filled the fuel tank with 50% E85 (ethanol-fuel) and drove to the car inspection. Got CO2500 0,5 (max allowed 0,2).

 

Problem nr. 1 

Last weekend I removed the screws for the heat shield for the catalytic converter and found 2 cracks on the exhaust manifold. I think this is my problem. I had a tube of fire proof compound for fireplaces/chimneys and put on the cracks and did a new exhaust test today but got the same resault as last time. Maybe the sealing did not work (I know it is a cheat "repair") or there can be more cracks on the underneth.

Solution: Buy a new catalytc converter

 

Problem nr. 2

Battery gets drained during weekend if not disconnected. Thank you Pete! ECU relay sounds like a good guess. I have not done anything yet, must get it passed inspection first.

Solution: Investigate

 

Problem nr. 3

Since last time I have also got ABS and ESC light which i must fix to pass inspection. Last winter I got ABS+ESC as soon as it was a little bit slippery outside. Last half year maybe once a week but now it is only off a few meters after i start driving the car. The fuse on the battery looks ok, I guess start with bearing and then ABS sensor? I have fault code rear right.

Solution: New wheel bearing and/or ABS sensor

 

Problem nr. 4

The car has been leaking glycol somewhere around the lower radiator hose conection to the radiator for 2 year but it is leaking more and more. Now I fill every third week. use to be less during summer.

Solution: Replace radiator and lower radiator hose (bought new parts two years ago but has not replaced them yet)

 

Problem nr. 5

Is not a problem with the car but maybe the biggest problem for me. My right HIP hurts of driving at 80km/h (50Miles/h) 90km (56miles) each day. Have not had any problem with previous cars but with this one it is something that does not fit me. Maybe the short seat/lack support for the thighs which I have improved by adding some bits of wood under the front edge of the seat frame. I am thinging maybe the gas pedal is a little bit to stiff? 

Solution: Try to make the pedal easier to operate / Install cruise control. Do VAG need to do somehting if I try to fit aftermarket cruie control?

 

 

Some days I feel like i want to scrap it and buy somehting newer. I get 10000 SEK (727 GBP) from the goverment if I scrap and buy an second hand electric car which had suited my driving well for most journes. But on other days it feels like the car is way too good to be scrapped. Gear box is good, clutch i good. engine is probably still good, rust is ok and it is a very practical car. My tow bar rusted away last year but I fitted a second hand tow bar 5 moths ago.