20 Most Recent 1999 Toyota Corolla Questions & Answers

The catalytic converter has an oxygen sensor in front and behind it. When the vehicle is warm and running in closed loop mode, the upstream oxygen sensor waveform reading should fluctuate. The downstream O2 sensor reading should be fairly steady. Typically the P0420 code triggers the Check Engine Light if the readings of the two sensors are similar. This is indicative of (among other things) a converter that is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system.
Symptoms You will likely not notice any drivability problems, although there may be symptoms.
Causes A code P0420 may mean that one or more of the following has happened:
  • Leaded fuel was used where unleaded was called for
  • An oxygen sensor is not reading (functioning) properly
  • The engine coolant temperature sensor is not working properly
  • Damaged or leaking exhaust manifold / catalytic converter / exhaust pipe
  • Retarded spark timing
  • The oxygen sensors in front and behind the converter are reporting too similar of readings
Possible Solutions Some suggested steps for troubleshooting a P0420 error code include:
  • Check for exhaust leaks at the manifold, pipes, catalytic converter. Repair as required.
  • Use a scope to diagnose the oxygen sensor operation (Tip: The oxygen sensor in front of the catalytic converter normally has a fluctuating waveform. The waveform of the sensor behind the converter should be more steady).
  • Inspect the downstream heated oxygen sensor (HO2), replace if necessary
  • Replace the catalytic converter
One thing to note is that many vehicle manufacturers offer a longer warranty on emissions-related parts. So if you have a newer car but it's out of it's bumper-to-bumper warranty, there still may be warranty on this type of problem. Many manufacturers give a five year, unlimited mileage warranty on these items. It's worth checking into.

1999 Toyota... | Answered on Dec 03, 2019

try to change your fuel filter, that is the most common cause of that problem

1999 Toyota... | Answered on Sep 08, 2019

Here ya go. This should cover everything. Including known values

1999 Toyota... | Answered on Feb 19, 2019

Check out this video. good luck. http://www.youtube.com/watch?v=mQmpLjYryRw

1999 Toyota... | Answered on Sep 10, 2018

adjust the accelerator cable.

1999 Toyota... | Answered on Apr 13, 2018

There is a digital stepper motor installed in the idle air control valve and it is operated by the ecm after taking all the outputs from various sensors.
Check engine light error code 33. The idle air control valve circuit open or shorted to ground. There could be three possibilities which can trigger this code and the check engine light comes on.
1. Check the wiring harness for open circuit or short to ground. Check the idle speed control valve connector for looseness,corrosion of poor contacts. Jiggle the harness at various places to find any damaged wire.
2. Idle speed control valve defective. (replace. Merely replacing the electronic part of the valve can also solve the problem)
3. ECM defective. (replace)

1999 Toyota... | Answered on Mar 17, 2018

Could it have timing belt issue?

1999 Toyota... | Answered on Feb 12, 2018

Reset the computer with a code machine or by taking negative cable off battery wait for 2 minutes put it back on the light should go out if it don't you have a problem within the abs system

1999 Toyota... | Answered on Jan 30, 2018

It should be in the fuse panel under the hood drivers side next to battery

1999 Toyota... | Answered on Jan 30, 2018

I would find a mechanic that knows what he is talking about. A damaged fly wheel will cause noise and very rough unbalanced running.

1999 Toyota... | Answered on Jan 15, 2018

just look at your fues block with a flashlight and you will be able to see the blown fuse... look closely it might not be obvious at first. Another thing you can do is go to the store and purchase a fuse tester... a simple device that has a pair of pins (actually they usually have 2 pair, one for two different spacings) and an led... you put the pins against the fuse's exposed metal contacts on the flat back and if the fues is blown and the device is on, the led will light... you may have to buy a fuse kit to get the tester but they are well worth it, along with a fuse puller, if you are like me and have large fingers

1999 Toyota... | Answered on Jan 07, 2018

Check you brake fluid, If its low when you go WOT the fluid will move away from the sensor and the light with come on and take a few seconds to reset

1999 Toyota... | Answered on Jan 03, 2018

Go to Bing homepage here is a link to many photos of the diagram

1999 Toyota... | Answered on Dec 03, 2017

first have the fault codes read
the consumption indicates flooding so it could be excessive fuel pressure, bad injectors , injector seals , blocked cat converter MAF/VAF sensor or heated oxygen sensor in the exhaust manifold
what the problem will be in the codes

1999 Toyota... | Answered on Nov 24, 2017

Have a compression test done on your engine; my guess is low compression on those 2 cylinders. If that is the case, a rebuild of either the head or the whole engine is the solution.You might also check with your local Toyota dealer if there is an updated valve cover for that car; they had problems with the 3.0 V6 engines in that regards, not sure about the 4cylinder.

1999 Toyota... | Answered on Oct 15, 2017

look in the under hood fuse box for a 100 amp battery fuse. chances are that will be the one.

1999 Toyota... | Answered on Sep 01, 2017

get the help from the car repair manual then you will able to fix the problem go to the given link for manual http://toolsnyou.com/

1999 Toyota... | Answered on Aug 24, 2017

Use an oem parts site with assembly breakout diagrams like the link below to see if you are missing a clip.

1999 Toyota... | Answered on Aug 18, 2017

Hello Chelsea

There are only three places you can lose oil.

From the valve stems. This burns oil and it will be present in the exhaust. It is the least expensive to fix as only the cylinder head has to come off.

From the piston rings and especially the oil scraper ring, (two compression rings and one oil scraper ring). This requires engine removal, a rebore, new pistons and rings. This also causes oil to be burned in the combustion chamber.

Oil leaks from joints in the external seals to the engine, the sump for example. Also from the oil breather pipe. You can check this by sliding a piece of carboard after you park and check it before you drive next time. Any POOLS of oil signify a leak.

By you saying your oil is black, signifies oil is seeping into the combustion chamber and being partially scraped back.

Check the compression with a tester, and measure against what compression is supposed to be. You can Google this.

1999 Toyota... | Answered on Aug 14, 2017

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