What to do when the car feel sluggish and gear jerk

After years of driving suddenly you feel the car becoming sluggish and the gear starting to jerk especially when reverse or braking while on gear D. This is common behavior for most cars when it is getting old. So, what is first thing to check when it happens. 

The most basic thing to look at is the battery connection - make sure nothing loosely tightens and if so, tighten it accordingly. Loose battery connection can be the main culprit in sluggish car as the engine sensos such as.

MAF - Mass Air Flow Sensor

MAP - Manifold Absolute Pressure Sensor

IAT - Intake Air Temperature Sensor. 

TPS - Throttle Position Sensor

ISCV - Idle Speed Control Valve

ECT - Engine Coolant Temperature Sensor

CMP - Camshaft Position Sensor

CKP - Crankshaft Position Sensor

OCV - Oil Control Valve Solenoid

Knock Sensor

As well the spark plugs, fuel injector, fuel pumps

The sensors and components above require efficient electrical signal to communicate them between Engine Control Unit (ECU / ECM / PCM) effectively.

Meanwhile on the transmission side the gearbox solenoids and sensors require efficient current to communicate with the transmission control unit (TCU). 

Therefore, make sure the battery connection is tightly.