Missfire, Injectors Or Blocked Cat ?

[the-bazman]

hi all , im new to the forum so im sorry if this has been coverd before

had a misfire on cylinder 2 in december . fitted new plugs as they havent been changed for awhile . still got the misfire so i changed the coil . engine light came on again and car still miss firing. left it for a little while as i run out of money . put it back on the computer beginning of the month at lexus themselves and it came up with

p300 missfire

p301 missfire

p302 missfire

p303 missfire

p0171 system lean

o2 sensors are ranging and heater circuit is working .

they advised me to renew coils . so i did but still got same problem . saved some more money but im really stuck on where to go next . please help if anyone can

[ROYT]

Try cleaning the injectors.......

[the-bazman]

ok will do . whats the best stuff to use ? thanks for the reply mate. had over 80 people read this post and no one replied

[ROYT]

Carb. cleaner is probably as good as any, most popular solvents are widely used

cellulose thinners, petrol and paraffin mixed etc.

Best is an 'ultrasonic clean'.

Whilst they are out,disconnect the coil/s [for safety, you dont want any sparks] and put some rags over the outlet from the fuel rail and switch the ignition on for a couple of seconds to flush some fuel into a clean jar. Check this for any dirt/water/rust etc. to confirm clean fuel.

Fuel filter might need replacing if it's dirty, reducing fuel pressure .

[clifton 94]

hi could be the cat in the exhaust manifold

[the-bazman]

ok will do , thanks again roy. will try the injector route first , failing that will have a look at the cat, cheers clifton

[mikey g]

Hi baz , i am getting the exact same readings and have done everything you have done( new coils plugs) and still no joy ,

mine starts ok first thing then after ten minutes of driving starts missing until it has stopped and cooled down then its ok again for another ten minutes , its driving me mad .

have you had any luck yet ?

[NunoFil3]

Hi guys i have exactly the same problem misfire cylinder one but just when the engine is warm in cold runs fine for while, have change the coil packs, spark plugs and still the same code 1301 and sometimes 1171 too.

It is making me crazy let me know if any luck i will let you know too if i find a solution.

Another thing is do we have to drain the entire radiator fluid to remove the injectors and how hard is that to DIY.

Thanks for sharing