My 2003 rav 4 4wd is actinmg strangely, sometimes if u r driving, n depress the gas pedal, it doesnt respond, but the rpm continues 2 increase, till after abt 4 secs, it wud kick in, with a soft thump n the car will now accelarate!...this haoppens intermittently..what cud be wrong with it?

.The control module provides the APP sensor a 5-volt reference circuit and a low reference circuit. The APP sensor then provides the control module a signal voltage proportional to pedal movement. The APP sensor 2 signal voltage is low at rest and increases as the pedal is depressed. When the control module detects that the APP sensor 2 signal or the APP sensor 5-volt reference voltage is outside the predetermined range, DTC P2125 sets.

The control module provides the APP sensors a 5-volt reference circuit and a low reference circuit. The APP sensors then provide the control module signal voltages proportional to pedal movement. The APP sensor 1 signal voltage is low at rest and increases as the pedal is depressed. The APP sensor 2 signal voltage is also low at rest and increases as the pedal is depressed. One APP sensor DTC will not cause the Reduced Engine Power message to be displayed. Two APP sensor DTCs for the same sensor also will not cause the Reduced Engine Power message to be displayed. However, if two or more DTCs are set involving more than one APP sensor, DTC P1125 will set.

seems like it's going into limp mode intermittently i would try cleaning crack shaft sensor. or replace.

Is the car equipped with the Automatic Transmission?
If so, read on.
Otherwise skip to the end and answer some questions.

POSSIBLE SCENARIO:
I have observed a condition where my car surges slightly when the torque-converter clutch (TCC) cycles between lock and unlock when driving on an uphill grade.
First some basics and history that will explain why the TCC is used.

Engine, Torque Converter, TCC, and Transmission relationship--
The TCC allows for a solid connection between the engine and transmission which allows the input to the transmission to rotate at the same speed as the engine.
Without a TCC, there is slippage between the engine and automatic transmission. The slippage is greatest at low engine RPM. That is what allows the engine to run with the automatic transmission in gear, like when you first shift into gear or stop at a stop sign. When the throttle pedal is depressed, the engine RPM begins to increase and the torque converter begins to slip less and less the more the engine RPM increases. The car moves. But even at cruising speeds the torque converter slips slightly. Engine RPM is greater than transmission input RPM, which is realized as slight decrease in fuel efficiency.
When acceleration is complete and a constant speed is being maintained, the engine power output is reduced to the point where the TCC can engage and eliminate any slippage between the engine and transmission. If the car has a tachometer the engagement of the TCC can be verified when a slight reduction in engine RPM observed without a corresponding change in vehicle speed.
One method used to test the operation of the TCC is as follows:
Find a flat section of road where it is safe to perform the test.
Reach a steady speed and keep the gas pedal depressed with one foot. While observing the tachometer (or listening for an increase in engine RPM), with the other foot depress the brake pedal enough to activate the break light switch but not enough to engage the brakes. When the brake light switch activates, the TCC receives a signal to disengage. With the gas pedal being held steady, release the brake pedal and the engine RPM should decrease when the TCC engages.
Old cars with Automatic Transmissions did not use a TCC. I believe the TCC was put in use in an attempt to increase fuel economy.

MY EXPERIENCE WITH SIMILAR SYMPTOMS
The condition that causes that issue on my car is this:
- A slight uphill grade increases the load on the engine.
The car tends to gradually slow and it is necessary to depress the gas pedal to maintain speed.
- Depressing the throttle pedal (manually, or automatically with cruise control engaged) signals the torque converter clutch to unlock when the load increases slightly. (A more drastic load increase would signal the Transmission to downshift to a lower gear.) The corresponding increase in engine RPM and output is enough to compensate for the reduction in speed. When the vehicle speed, engine RPM, and throttle position stabilize to the point that the TCC will engage and the engine RPM will reduce in correspondence with TCC engagement. Now, if the road conditions have not changed, power output is not enough to maintain vehicle speed. With the increased load caused by full engagement between engine and transmission, and the cycle (surging) repeats itself until the road conditions change.

Does that help?
If not:

QUESTIONS
Please define the symptoms.
What are the road conditions when the surge occurs? (A slight uphill grade?)
What is the frequency of the surge?
Does the engine power output have a noticeable surge?
Is there a speed change related to the surge?
Does the tachometer move up and down with little or no change in vehicle speed?
Are all instrument indication in the normal range?
What else has changed?

Good luck!

You have a mechanical bind. Disconnect the main linkage and work it all by hand. Everything should be free and slopy. Aerosol carb cleaner will help, but only when the engine is not running.

almost sounds like the cruise control is engaging

the gear box needs inspection--hav an honest mechanic drive it or a trans specialist--may need some rebuildin--not a big deal since its a standard

Your all over with this
I wish I could drive it
I own a 2004

Why was the MAF,not MAS changed?
I know the EGR Valve problems
I also know the idle and shift stratagy

Is it a V6 or V8
Give me some history on COP Coil issues
and other past problems

Do you work on it exclusively?
If repair shops have checked it ,I need all they did
in detail. Their no good with an LS and a dealer is lost

The idle won't go over 3000 rpm in park,it is a safety feature without getting technical
When you go into drive it should not increase in rpm
The throttle command comes from the pedal actuator (gas pedal),I will continue later on that

MAF Sensor shouldn't fail,was it tested and how?
How many coils went bad since 2003?
Was TPS checked out?

Has a dealer ever looked at it,looked might be a stretch,their not good at even looking
and can't fix these cars.

I will wait on some input from you

Inspect brake booster vacuum line from engine intake to brake booster for leaks also inspect brake booster check valve, more than likely your brake booster is causing a vacuum leak to your Intake thus leaning mixture wich increases idle rpm

This problem could be as simple as a TPS (throttle position sensor). Some vehicles are now drive by wire. This means that there is no actual throttle cable. When the gas pedal is depressed, it sends a signal to the CPU and tells how far the pedal has been pushed. How many miles do you have on this? Sometimes a plugged catalytic converter can cause a vehicle to accellerate slowly and cause you to "butterfly" the pedal and make it hard to get over 60-70 MPH. Hope this gives you some ideas.

one unit that operates ratio changes and is connected to the engine is that vacuum operated actuator on the transmission
it is possible that that unit is failing , vacuum hose is leaking and that will cause ratio changes as the vacuum varies
run the fault codes to check for wiring problems or VSS or TCM problems as well