6G Celicas Forums

I saw a lot of posts about the p0401 code, but i can´t find somebody wich fix this code. i already did all this changes to my car.

i changed the next list:
spark plugs wires
spark plugs
distributor cap and rotor
head gasket
fuel pump
fuel filter.
MAP sensor

cleaned:
EGR valve
IAC valve
checked all egr vacumm lines

and i have same problem, same p0401 code, my car its on very slow rpms it shakes on any speed (10, 30, 60 MPH) and i have no idea what else to check to fix this problem ... did someone else having this problem and got fixed??

thank you!!

I'd start with mild stuff like run premium gas AKA 91 for NA or run 93 for turbod. I'd recommend running on high quality gas. I run 89octance Chevron gas in my lil 5sfe daily. Run like that for a week and see if there's any difference. If not then use Lucas Fuel Treatment or the Sea Foam.

Btw, you meant the engine would shake like as in it would stutter like its about to stall?

It's an EGR code, which means it'll be one of four things: EGR valve, EGR modulator, EGR solenoid, or EGR temperature sensor. The solenoid and temp sensor can be tested with a multi-meter. When you cleaned the EGR valve did you also clean the tube? Usually the tube will get clogged up causing the problem.

Here's how to test for the 7A-FE, it's close enough to the 5S to give you a better idea on what to do though: http://ww2.justanswer.com/uploads/skyvisio...44_95_rolla.pdf

That´s right .. some times in stop light the car just stalls..

i had cleanded the tube but with the valve out of engine. let me check this link. thank you a lot guys!

Usually the modulator has failed, the diaphragm inside is torn and the modulator must be replaced.

That, what ended up happening to mine after running through all of the tests.