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Merc320, Technician
Category: Mitsubishi
Satisfied Customers: 330
Experience:  City & guilds pt 1 & 2
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I have a 2001 Galant, with 4G94 GDI engine. I have low

Customer Question

Hi, I have a 2001 Galant, with 4G94 GDI engine. I have low power/misfire problems. If driven with very light throttle, it can get to 3rd gear and approx 80kph. If the throttle is applied quickly , the engine just bogs down and the car slows. I purchased the car like this. Previous owner had it looked at, 3 coils test faulty, and the s/plugs were replaced. The MAF was swapped for another with no change in running. I have changed the coils, checked the main supply fuel filter and the small filter on the high pressure pump. With a scan tool, I find I can achieve 4000rpm before it starts to miss, and the ignition timing advances to 25 degrees, approx 30% engine load. If I apply throttle quickly, the engine bogs down and misses. The timing is only 5 degrees, with engine load of approx 80%. When releasing the throttle, the timing advances. It has 4 codes, but my scan tool will only let me see 3 P0135, P0105, P0110. I think I caused p0135 when disconnecting the oxygen sensor to remove the exhaust shield. The CEL wasn't on before this. I can't clear the codes with the tool I have, for some reason.
Submitted: 3 months ago.
Category: Mitsubishi
Expert:  Dan replied 3 months ago.

Hello, my name is ***** ***** I'm here to help get your problem solved.

Expert:  Dan replied 3 months ago.

Have you tried to completely remove front oxygen sensor from exhaust to see if that allows it to run better?

Customer: replied 3 months ago.
I have just tried that now and it has the same result. One thing I didn't mention, if the throttle is used quickly and the engine bogs down and miss's, as you release the throttle the engine revs pick up before coming back to idle.
Expert:  Merc320 replied 3 months ago.

Hi my name is ***** ***** am here to assist you.

Have you got an inter cooler , if so check the hoses for splits or leaks.

Srry if this seems a simple question but i have to start somewhere.

Customer: replied 3 months ago.
Hi, naturally aspirated engine.
Expert:  Merc320 replied 3 months ago.

Hi ok

Can you get a compression test done.

Customer: replied 3 months ago.
Have done a compression test today. 2 @230psi, [email protected] and 1 @ 235psi. I have removed the knock sensor, as it has a sticky residue coming out of it, I will get checked by a electrician tomorrow, as well as rechecking the coils. I suspect the knock sensor is faulty and causing the timing to retard under heavy throttle. It is a 2 wire sensor, number on the plug is E1T15677. What voltage should be at the wires going to the ECU, if any?
Expert:  Merc320 replied 3 months ago.

When you refit the knock sensor it has to be torqued to correct setting.

I am struggling to see this being youre problem.

keep me informed please.