Hi all, I have a Honda S-MX, 1997 with a B20B motor.The cat converter light comes on 2-3 minutes into my journey from a cold start, stays on for a bit, then flickers out.Sometimes comes back on when I accelerate and then gradually flickers off again.Once the engine is nice and hot the light stays off.
Its getting worse, in that now when I stop for 10 minutes and restart, the light will come on briefly.
I havent read the fault codes yet (waiting for my OBD scanner to turn up from China) but it sounds like the sensor heater is playing up - I will check for loose connections around the sensors, but does anyone have any other thoughts / suggestions!
I recently put a new thermostat in about 2 weeks ago - prior to that the engine was running permanently cold.Would this cause the ECU to keep the sensor heater on for longer, and consequently burnt it out!
doriandarby,
Apr 15, 10:14pm
Forgot to mention - the Check Engine light does not come on and no flashing codes show up when I jam a paper clip in the diagnostic socket (only the ABS fault codes, which is another matter!)
rkauto,
Apr 16, 3:06am
your obd scanner will be no use on it
doriandarby,
Apr 16, 3:32am
Why so!
intrade,
Apr 16, 3:38am
you want to go and warm it up and go for a blast in low gear at high rpm on the motorway. . you need the car serviced so nothing fails like timingbelt when you give it a good thrashing to redhot glow the cat converter as i think Your problem is . nana driving and the cat converter never got hot enough and now starts to block and cause problems.
jmma,
Apr 16, 3:52am
Yes, if you make a statement like this, you need to atleast back it up and say why it will be no use.
doriandarby,
Apr 16, 3:54am
intrade - I can see where you're coming from, but why does the light only come on when the engine / exhaust is warming up, flickers, and then is off for the rest of the journey!
Wouldnt a blocked cat cause the light to be on all the time!
rkauto,
Apr 16, 3:55am
honda use a 2 and 3pin diagnostic plug.obd will be 16 pin.
doriandarby,
Apr 16, 3:56am
But Honda have also been fitting 16P ODB connectors since the mid 90's, according to my research anyway.
rkauto,
Apr 16, 3:57am
you will more than likely have an ignition issue.Unburnt fuel burns in the cat causing it to overheat .check leads ,plugs etc first.
intrade,
Apr 16, 3:58am
its not blocked but not working right its why the cat light flickers because it detects its not working right and then it just comes right, We needeed to rev the crap out of loads of cat converter cars from the 1990s when i was doing emission testing in europe to get em to operate right so i could print out the certificate of emissions
doriandarby,
Apr 16, 3:59am
Now that might be something - I recently put new plugs in.Old ones were all nicely light brown but worn electrodes.Replaced with same model of plug.Not long after, this red light comes on.But there's no evidence of misfire, so cant see how new plugs would do this!
doriandarby,
Apr 16, 4:02am
Recently replaced the thermostat too - so now the engine is warming up.Car idles nice and low when its hot (approx 700rpm) so I'm fairly sure the ECU is being fed the correct engine temp.
But.There has to be something buggered!
paulie12,
Apr 16, 4:04am
I had the same problem with my suzuki escudo. Had my cat converter removedpipe welded in an earth it out $83 later done!
ralphdog1,
Apr 16, 4:04am
Not completely true, the 96 CRV we have does not have an OBD2 connector, and believe me I have looked.
intrade,
Apr 16, 4:05am
just go for a blast. the thermostat was out means it was running rich would have clogged the cat now you got to clean it out . Go toa engine emission tester and put a sond in the exhoust i would bet the HC emission be off the scale untill you get the cat to work. faulty cat stink like rotten eggs these need also a thrashing when they stink like that.
intrade,
Apr 16, 4:06am
you can do that but you want the o2 sensore in place or it be chewingfuel like hell after and a muffler in place off cat or it be to noisy .
intrade,
Apr 16, 4:08am
96 japanese has have had no obd back then only 2003 on some japas usa cars and european like vw had obd2 in 96
doriandarby,
Apr 16, 4:09am
I think I might just give it an Italian tune-up, as Intrade recommends :)
When you say, go for a blast, what exactly do you mean!What sort of revs and for how long!
doriandarby,
Apr 16, 4:10am
Well thats bloody strange - I've been using a Honda factory workshop manual (for a CR-V though) which shows the location of the OBD connector for models 97->
intrade,
Apr 16, 4:12am
wellifrev counter is redlining at 6500rpm then you keep it at 5800rpm for 4 minutes just check temperature from engine coolant dont climbs to far as it should not unless there is a problem then down normal then 1 minute just before redline and then normal again that should do it.
doriandarby,
Apr 16, 4:15am
sweet as.I feel a drive coming on.
Fuel economy does seem to be crap, but I havent driven it enough to know for sure if its got worse recently or not.
intrade,
Apr 16, 4:15am
could be if you got obd2 plug but japanese where slow in adopting obd2
And I have the same manual that also shows location of the OBD2 connector. If you lived down my way I would invite you round to find it, and were you successful would offer you a doz beers, cause I can't. I think you will find that you have a Yankee manual where OBD2 was mandatory from 96 on, but that did not translate to it being fitted to JDM stuff. My 96 Surf is the same, can find it in my Yank manual, but there is not one in the vehicle.
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