Loss of power

2002 LEXUS IS 200

230,000 MILES • 2.0L • 4 CYL • 2WD • AUTOMATIC

NDEERE

MEMBER
1 POST

The car has been losing power and jerks/vibrates while in low gear. We have changed coils, did resurfacing to avoid chamber leakage, changed injectors, changed oxygen sensors, but no change. the error showing is 'too rich' and 'too lean' both at the same time. what could be the problem?

May 8, 2019 at 2:09 AM

ASEMASTER6371

✓ASE Certified Mechanic
52,796 POSTS

Good morning,

The first thing I always suspect with low power complaints is the filter. Check or replace the fuel and air filter.

https://www.2carpros.com/articles/engine-has-low-power-output

I did not see the plugs as a replacement? That is the second thing I would suspect.

What is the error codes you have in the system?

I would also check the catalytic converter for partially being blocked.

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

Fuel pressure is a concern as well.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Roy

Images (Click to enlarge)

Professional Diagram for 2CarPros Members
Click here to log in and view diagram.

May 8, 2019 at 4:11 AM

JIS001

✓ASE Certified Mechanic
3,412 POSTS

Hello and thank you for using 2CarPros. If the fault is mostly in idle and have fault code P0300 or any misfire codes then your intake valves are full of carbon. If that is the case then you would need to do an engine tear down and replace the pistons and grind down the valves.

May 8, 2019 at 10:42 PM

Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.