Hey all,

I have a 192, 2007 RX. When i start it first thing it idles fine until the choke drops down to 1500 it will start missing and flash up a DTC (checked the fault came up with Cylinder 2 misfire) not long been serviced so plugs are ok and changed coil. But when i drive it.. after 5mins the light goes out and drives fine?

Also i noticed when going up hill and put my foot down there is nothing there, i'm constantly changing down gear to go anywhere. Especially compared to the 230bhp edition.

We have done thorough diagnostics on it, supposedly the MAF sensor is a common cause of these symptoms??

Rather have a backed up diagnosis from both a computer and people first hand experiance's

Cheers

 

Moved to Troubleshooting.

You mentioned "coil", not "coils", did you change all of them?

It sounds like ignition failure for the stumbling. Ignition failure usually leads to cat clogging, which will rob you of top end power more and more the more it fails, and once it starts failing, it will keep failing even with good ignition.

Clean your e-shaft sensor, MAF sensor, reset your fuel trims and e-shaft profile anyway, they are good to do periodically. But you likely have a failing cat now.

 

Yeah i will try the cleaning.

The cat I can understand but has gone through emissions perfectly fine. Might not show anything as such. Would a small defect in the cat show good emissions? cause i know they are some sort of super cat with ther heaterplugs etc along with the Lambda sensors.

Its more of when you have your foot at a certain point on the accelerator its fine (on flat) as soon as you go for a bit of power its flat.

 

Everything RIWWP said plus 1 - get a compression test done on the motor too. Low compression will also initially start showing up as a performance issue under Wide Open Throttle (WOT). It will eventually progress to other issues such as hard starting once motor is warmed up and so on. If you have someplace to take the car where you can safely run it at full throttle up to the highest speed it can achieve on a flat road this can be used as a "seat of the pants" test too. Loss of top end terminal velocity over time under equivalent environmental conditions, etc is a telltale that compression is falling, cat is clogging, or both.

 

Intuition is clogged CAT - easy way to tell is drop the CAT (3 bolts) at the exhaust manifold and look to see its condition.