RicardoM

Use High Performance Gear Oil (GL4+) SAE 75W-90.

First of all, some theory: And another bit of theory: The conclusion is this: you need a GL4 gearbox oil given you live in a hot weather region, you need a 80W90 oil My recommendation is to buy 3 liters of this oil: https://www.mannolegypt.com/products/manual-transmission-oils/universal-80w-90/

What country do you live in? I'm asking to see what products you have access to.

Of course it idles rough, yet you didn't mention it when doing your test. The MAP sensor (corrected with temperature) is measuring the load of the engine. Based on that and on many other factors, the ECU sets the injectors, spark, and timing. The engine is stalling when the fuel mixture is out of limits (too lean or too rich) based on bad data from sensors. By the way, a bad coolant temperature sensor can stall the engine too and create a no start issue. That is why I don't recommend swapping parts blindly. Yeah, you might solve the problem by pure luck, but usually things don't go well.

How nice. According to this experiment, the map sensor is useless The car runs fine without it. Why bother buying a new one?

How would you describe your car mechanics skills, diagnose knowledge, and available electrical measuring instruments?

Mike IIRC you're half way in your 70's. You're asking a very subjective question with many human variables that we have no clue about. My intuition tells me it is better to let a garage do it.

Read my signature. Fuel System & Ignition / Simos 2P / Simos 2P Fuel Injection & Ignition System / Page 24-22 Engine / Engine 1.3 (135, 136) / 1.3 Itr. Engine, Mechanical Components / Page 20-18

Since you have found several connectors having corrosion, I would have a look at all of them in the engine bay. Also it might worth taking a look at electrical pump connector too. That is why I asked about the throttle pedal. If the throttle position sensor (fancy name for the potentiometers that sense the throttle flap position) has developed a groove or some worn spots around idle position and cruising positions, then you have the culprit right there. Do you have the factory service manual for Felicia?

One other thing. Does the juddering appear only when the throttle pedal is pressed approximately the same amount? Let's say around 10-15% of wide open throttle? Or is it the car judders also if you keep the pedal pressed constant at let's say 50% then slowly press further?

That is not a throttle reset.

Most probably it is the knock sensor. The third wire is the shield that goes to the ground only at the other end of the cable.

I can't see where it is located.

My recommendation for now is stop looking for parts before having evidence of fault. Clean the throttle body. Reset the throttle body. Not sure if Launch X431 can do it. I plan buying one.

I don't know if that will solve your problem but it definitely worth spraying the contacts with contact spray or WD-40. What mileage has your car? First advice: erase all codes and check after 2 engine starts if and what errors come back. If there are errors, paste their code in here. Add the freeze frames (engine parameters when the error was set) too.

We're talking about this

@Jordan975 There are many topics about such project. Search both in this section and in section Classic SKODA Projects.

mike Is there any reason you think it is the switch that is faulty?

I would be very interested what is RossTech's review on OBD11

If not in turn, is it possible to reset all misfire counters at once?

I'm talking about these counters.

Hi Can I reset the misfire counts for each cylinder in turn ? How?

Did you use the clay bar to remove any wax used as paint protection? Or do you have another method as wax remover?

What clay bar did you use? What quantity? What did you use as lubricant?

UPDATE The outside temperature dropped by some 5-10 degrees. The BCM started to command the alternator to charge harder (for the same electrical load I have used for the last 2 weeks). The voltage on battery stays at 14.7-15.1V 90% of the drive time. In the morning I have measured a higher and higher voltage. Today the voltage was 12.4V. We're getting there... My conclusion so far is that the firmware in the BCM seems to know how to handle the SOC of the battery. Not having access to the firmware source is a drawback but given the proper free time I could deduct the charging strategy by studying relevant logs.