Hi Guys, Please bear with me have a long story to tell.
Had some trouble with my 99 plate 1.6sx 16v Brava.

It started with the dreaded injector light coming on and staying on at low revs. I looked through this forum and found it was a comon fault normally being an injector failure. Sure enough I had two open circuit dead injectors.

Replaced both dead injectors with some 2nd hand ones from the breakers and have an average reading of 16-15 ohms across all four injectors. Car fired up lovely and have no more injector light. Took car for its mot as it was nearly due.

It failed on high emissions. fast idle co level is 0.72. 2nd fast idle co is 2.84 and natural idle co is 3.89. Also the examiner complained he had trouble getting the car to hold 2500 rpm as it would drop to 1500 rpmm then race to 3500 rpm. this was not a problem before the injectors.

Has any one got any ideas? maybe a dodge 2nd hand injector? maybe some sensor or another has failed? Any ideas or tips would be greatly received. thank you.

do you have the results for HC and O2? was the lambda in range?

when you suffer injector failure you can damage the plug & lead on any cylinders that had a faulty injector. that is why i have always recommended these parts are replaced when you do an injector. the first time i replaced an injector i did not do this, and i suspect the weak ignition on one cylinder allowed fuel to enter the cat, causing my cat to burn itself to death (literally glowed bright red! i thought the car would set on fire)

considering your very high CO the lambda sensor and plugs/leads would be my first choice. if lambda fails or reads low the ecu will run rich creating high CO. if plugs/leads give weak ignition the misfire can easily be undetectable (no injector light) but still cause high CO.

the wandering rpm is another clue, but sadly that is another symptom that can be caused either by a bad lambda sensor or weak ignition, although considering the odds i would say this symptom it is more likely to be caused by a lambda sensor problem rather than weak ignition.

after injector replacement you should always replace all 4 plugs and leads as a matter of course, so get that done. if that fails to fix it then do the lambda sensor. if that fails to fix it then we need to carefully examine all the emissions test results (at that point in time) to decide what is occuring.

Hi Jug, thanks for your response.

Fast idle test :- rpm was 2596. co level 0.72 which was a fail max range 0.30. hc level is 102 which was a pass,max 200. lambda is 1.019 which was a pass, range 0.970 - 1.030.

2nd Fast idle test:- rpm 2540. co level 2.84 which was a fail max range 0.30. hc level is 252 which was a fail ,max 200. lambda is 1.005 which was a pass, range 0.970 - 1.030.

Natural idle test :- rpm 810. co level 3.89 which was a fail max range 0.35.

Hope this gives more of a clear picture. I'm going to get new plugs and ht leads today to see if this improves the results, and i'll post the findings. Thanks for the advice.

My new set of ht cables arrived this morning from parts 4 u. Fitted them and a complete set of new spark plugs. Also disconected the battery yesturday and reconected it again this morning.Performed an ecu reset by turning on ignition for 30sec but not starting the car, turned off the ignition then started the car without touching the accelartor pedel and let the car idle for 15mins untill full tempeture was reached. Turned off the car for 2 mins then restarted.

Tried to hold the rev counter at 2500 rpm which it did hold for about 45 seconds (which was an improvement) then it dropped back to 1500 rpm for a few seconds then raced off at 3500 rpm and just kept cycling between the two rev limits.

Got the wife to sit in the car and try to hold it at 2500rpm while i looked around the engine bay for any clues. Noticed that lots of white smoke was coming from the exhaust and some liquid was dripping out the tail pipe. I'm assuming this is some sort of condanstion as it did'nt smell of any thing or feel like it was petrol.

The exhust fumes itself smelt very rich like an old car left on the choke for to long. I'm guessing my emissions are probably going to be high still as the ecu is probably adjusting the engine from a high mixture to a lean one giving me the different rpm without moving the accelartor. Are there any tests i can do with a multi meter on the lambada sensor? Found what i think could be the plug to it at the back of the engine bay behind a cover next to a 15a fuse and a red relay. I'm guessing that i probably need a new lambda sensor even though the mot said it was ok, just a little worried about spendind 80 quid or so and still not resolving the issue.

Any ideas greatly welcomed.

we dont know if the lambda is ok from the test results. it is in range, but we dont know how quickly it is switching or if it is giving an accurate reading. a new universal lambda for your car is only £30 at my local motor factor. you need to join the wires yourself, using the wiring connector and some of the wiring harness from the old sensor.

white smoke and liquid is steam and water, perfectly normal.

an emissions test will only take 5 mins so do it again to see what the result is now.