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Matt, Mechanical Engineer
Category: Toyota
Satisfied Customers: 22001
Experience:  BEng, Repaired my own cars and others for 20 years, worked in Formula 1 for 10 years
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Check engine light can not be reset, a stutter. car

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check engine light can not be reset, a stutter. car stutters. can't find problem. plugs, wires, ignition coils have be changed
JA: Does the light stay on, or does it blink?
Customer: stays on. it blinked the other day though.
JA: What is the model/year of your Toyota?
Customer: 1999 camry
JA: Are you fixing your Camry yourself? What have you tried so far?
Customer: at a shop. having problems deterimining the problem since they can not pull codes
JA: Anything else you want the mechanic to know before I connect you?
Customer: is there anything to do to fix the check engine sensor


if the check engine sensor is permanently on then there's a permanently lodged fault thats keeping the light on

so the next step should be to use a scan tool to plug into the OBD port and pull off the code and so point to the fault

I'd say that its likely to be a lack of fuel pressure or a possibly bad O2 sensor but its far cheaper in the long run to have the code read off 1st

Customer: replied 11 months ago.
Everyone is have taken it to says the problem is in the connection and it has shorted


if you mean the OBD port connection then the next step is to carefully examine the condition of the pins with a flashlight and if thats OK then check the wiring to the OBD port for any damaged insulation and crimped wiring

I'm assumiing that if you do plug in a scan tool you get no mcodes or sense out of the tool?

Customer: replied 11 months ago.
Correct. No scan codes


Ok so have to diagnose the old fashioned way

from your description I'd say its likely to be lack of fuel pressure or bad air leak on the intake

if the car idles poorly and has a general lack of power then start with fuel pressure of the power is OK then start with checking for vacuum leaks

Check the hose clips for tightness and inspect the trunking for any cracks or splits and also all the vacuum system, the small bore pipes and fittings for cracks and missing parts.

The best way to locate a leak is to have the engine running and warm and then spray lighter gas /propane around each joint in turn. If the engine rev's up you've found your leak.

Now you might think that spraying lighter gas around a hot engine isn’t wise, however the flash /ignition point of gas is about 400°C so you need a naked flame or spark to set it off and I’ve used this method for many years without incident.

Work your way through each possible joint one at a time and you should find it. I use a slightly flattened piece of brake pipe and some rubber hose from the can of lighter gas to provide a spraying 'wand' and allow a direct blast of gas into each area, especially those difficult to reach with large implements.

It’s also worth getting the fuel pressure checked as if this is low due to a blocked filter or faulty regulator or even a poorly pump will all result in insufficient fuel being delivered to the engine

Might also be worth cleaning out the idle speed control motor / valve as these get clogged up with carbon and some brake cleaner washed through helps free things off.

Might also be worth checking the wiring and connector to the airflow meter for any signs of corrosion or damage. you can do a quick fault find if you unplug the meter and run the engine without it.

if the engine condition is the same then chances are the meter or the connection to it is faulty

It’s also worth cleaning the MAF sensor wires, as they can get coated with dirt over time which then offsets the reading

Use some contact cleaner or brake cleaner to spray onto the wires to remove the dirt – on no account touch the wires with anything as they are very fragile

Customer: replied 11 months ago.
Could the catalytic converter be the problem


yes its possible, as they don't last forever

if you remove the oxygen sensors and peek into the hole at the cat brick you should see a regular honeycomb that is even all the way across, any deformity and the cat should be replaced

Matt and other Toyota Specialists are ready to help you
Customer: replied 9 months ago.
The problem was an injector was bad. Had to pull each individual injector