Question about Toyota Celica

1 Answer

Well i did not pass emissions a code 0420 came up when i go to push on the gas i takes a while to go so there is loss of power in my car

Posted by on


1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Expert
  • 273 Answers

The PCM copares switch rates between the front O2 sensors and the downstream catalyst moniters. The catylist moniters are often mistaken as O2 sensors, and they are, but that is not their job, or what they are called. By comparing the switch rates between the front (before cat) and rear (downstream of cat) the PCM knows if the cat is affecting the exaust, and how much it is affecting the exaust. If it sees little or no effect o the exaust gases that have passed through the cat, then it decides that the cat is not working anymore, ad sets a P0420, or a P0430, depending on which bank it is. To check this yourself, you will need to bring up data stream on your scanner, watch the upstream and downstream O2 parameters and see if they are following each other closely. If the cat is working right, you should see a fairly rapid switch rate, probably 5 or 6 times a minute on the front O2, but almost a flat line just above .5 volts on the rear. If the rear is switching often you proabably need a catalytic converter.

Hope this helps, James Booth!! PLEASE RATE THIS!!!:)

Posted on May 18, 2011


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Loss of power and surging on cruise control. Flat surface. 2013 ford territory

need more info as to why when the cruise control is locked in/set it is serging, i think your cruise doesnt work, or surging could be fuel line, filter, , loss of power could lso mean it is plugged up at the emissions end of the car try having sensors checked before and after the catylytic convertor this is very important, if there is no emissions testing where you are at/living disable the cat by either having muffler shop cut it, or just taking the sensors out if it can run like that, i was abl to just remove the sensors in front of the cat, but my vehicle wasa dodg ram pickup it sure saved me gas money and ran way better, the feds control emissions so if the law says you can have a car without it take it out.

Apr 27, 2016 | Cars & Trucks

1 Answer

Trouble code p1762

Code p1762 is the governor pressure offset volts too high or too low. This is a transmission solenoid that probably needs replaced. I believe that you have to take the pan off to get at it.

Apr 13, 2014 | 2001 Dodge Dakota

1 Answer

I went and filled my car up with gas and it started up

Im at a loss for what it could be ??????? That's understandable when you have no clue as how thing's work on a modern automobile . checked the fuel filter and fuel pump ???? How ? Fuel pump pressure an flow test . Voltage drop test the electrical circuit .
Testing Electric Fuel Pump Problems with Voltage Drop Test

Did you hook up a scan tool ? Not a code reader ! Check scan data ? What are the fuel trims at ? adding fuel taking fuel away ? Are the O2 sensors switching like thier suppose to ?

006 O2 Sensor Signal Analysis

010 Mass Air Flow Signal Analysis

Evap emissions system testing , stuck open purge solenoid . Over filled fuel tank . Do you top off the tank ? Or when fuel pump clicks off do you stop ? Loaded up the charcoal canister .
The Evaporative Emission Control System (EVAP) is used to prevent gasoline vapors from escaping into the atmosphere from the fuel tank and fuel system. The EVAP system usually requires no maintenance, but faults can turn on the Check Engine light and prevent a vehicle from passing an OBD II plug-in emissions test.
EVAP Evaporative Emission Control System -

Reading Scan Tool Data for Car Repair Auto Facts org

Jun 15, 2017 | 1995 Chevrolet Lumina

1 Answer

Just Failed my emission test......hc ppm reading 485 allowed 189 also CO% 10.50 ALLOWED 2.36 WHAT CAN I DO TO CORRECT.

sounds like a bad catalytic converter, just did my 1985 Jeep could not get it to pass ended up replacing the catalytic converter, muffler, ox sensor and EGR valve then Jeep passed with flying colors.
if your cat is bad it reduces your exhaust flow causing loss of power and increases fuel consumption.

Apr 30, 2012 | 1997 GMC Jimmy

1 Answer

I have a engine light Code P 0420, please tell me how to fix this & what is this. Its 2000 Honda Civic Ex $ door Sedan

Your Honda is probably very high on mileage. The P0420 code indicates that the catalyst system is operating below the efficiency threshold. In English, your sensors are telling your ECU that the catalyst in the catalytic converter is worn out. A new catalytic converter is going to be big $$$.

It is not going to disable your car, but if you live in a state requiring emission testing to pass inspection, your car will probably not pass the next inspection.

You can get a code reader (the Actron CP9575 or CP9175; both work well for less than $150.00 USD) from most auto parts stores or Sears and try clearing the code. In all liklihood, clearing the code this way will not fix the problem and the CEL will illuminate again.

Jul 21, 2010 | 2000 Honda Civic

1 Answer

Radiator fans fuses keep blowing-chevy impala 2002. we need info on following codes: P0108, P0128, P 0341, P 0401, P 0420, P 1480, and P 1481. John

p0108 map curcuit high input, p0128 coolant temperature below thermstat regulating tempurature, p0341 is camshaft position sensor A-bank 1 ckt range/performance, p0401 is exhaust gas recirculation, insufficiant flow detected, p0420 is catalyst system efficiency below threshold, p1480 is manufacturer control auxilary emission controls, p1481 is same as p1480.

Jun 15, 2010 | 2002 Chevrolet Impala

1 Answer

Car loss of power when i push on the gas

cheep gas you may have 2 put some octane booster a few.. fuel filter . catalytic converter..listen 2 the exhaust

Mar 10, 2010 | 1992 Cadillac DeVille

2 Answers

Will the lost of a gas cap hurt the cars take off power?

MAYBE. The loss of gas cap can cause water and dirt to enter the fuel tank, and fuel filter, and lead to a loss in power. get a new cap and the fuel filter repalced. the loss of power may be another problem, but you will need these items replaced first.

Oct 09, 2009 | 1992 Honda Accord

1 Answer

2001 Honda - New Catalytics & O2 sensors -- new 0420/1739/1456

I would send the car for a smoke test for the emissions leak...Find out where the leak is comming from..Repair it..Reset the codes, then do a drive cycle and see what happens...

Jun 29, 2009 | 2001 Honda Odyssey

1 Answer

Car losing compression

I doubt u are "loosing compression" more likely a sensor failure is causing a loss of power, go to any Kragen or Autozone and have them run a OBD 2 trouble code test, it is free, then post the code back here.

Apr 07, 2009 | 2006 Chevrolet Aveo

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

125 people viewed this question

Ask a Question

Usually answered in minutes!

Top Toyota Experts


Level 3 Expert

80637 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22326 Answers

Jeffrey Turcotte
Jeffrey Turcotte

Level 3 Expert

8841 Answers

Are you a Toyota Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides