Slow Acceleration `00 VE

[cast0r]

2000 Corolla VE 104k miles

About 10k miles ago I got two CEL codes. The car had a slow decline in power before I got the CEL.

One was the catalytic converter (a few months after replacing it)
The other one was System fuel to lean on bank 1.

So I went to work, changed the spark plugs, cleaned the MAF sensor, air filter, and oil change and oil filter, and did a can of spray in throttle injector cleaner.

After starting the car (in all weather conditions) I can drive it for a short distance (100 yards) then I stop at my stop sign to go on the road. While completely stopped the engine starts to idle really rough and would stall if I didn't hold the brake and give it some gas. In addition when I press on the gas pedal it would hesitate a lot. The car moves a little and the motor makes a very weird noise.

I've adapted by VERY slowly pushing on the gas pedal. Once I get past the 0-10mph it runs pretty smooth but the acceleration is really bad compared to when I bought it in 05 with 18k miles on it. When I push the pedal to the flood there is a 3-4 second delay before the engine kicks up the RPM's. And sometimes when I push the pedal to the floor it doesn't even kick up to the higher RPM's.

I have tried moving the idle all the way up but there is still a hesitation with the pedal.

I'm not very familiar with motors so any suggestions you have try to speak plain English!

[cast0r]

*bump

Can anyone help?

[fishexpo101]

What did the old plugs look like - were they pretty clean, just worn or heavily fouled?

Could be a number of things - vacuum leak, bad coil on plug igniter, dead cylinder or valve, bad PCV, bad MAF, faulty fuel pump, faulty ECT, faulty ECM, etc. Could be VVTi related, hard to tell for sure without standing right infront of the car.

Note that lots of issues will not throw up a CEL - so called "lazy" sensors, sensors that are intermittently working (slowly dying/failing) will generally not trip a CEL. Reading the plugs (noting gross differences between plugs) will help point you in the right direction. Checking for electical issue / vacuum leaks will take a good portion of your time - if intermittent, even harder to properly diagnose.

Does this go away or get worse after you do a hot restart? Does it go away or get worse when you restart with a cooler engine.

[cast0r]

The plugs were pretty dirty for I did not change them for over 75k miles. Just looked dirty, not malformed.

The MAF looked pretty good after I cleaned it.

The car could use a new air filter.

Is there a national car repair business where I can get a free inspection to check for faulty sensors and the other various potentiol faulty parts?

I only have problems with stalling after the car has been sitting for a while with a cold engine. Weather wise is acted the same in 70 degree and -10 degree weather with the stalling.

Will seafoaming the engine help?