4EFEJay Posted December 29, 2015 Share Posted December 29, 2015 Fitted a new exhaust to my Starlet EP91 at the weekend. New exhaust didn't come with anywhere to fit the old lambda sensor. So for now i've just left it unplugged. Will this cause any problems? It seems to idle and rev fine. It's purley a track car and will be driven on the road to and from track. Will it cause any damage? And will I see a loss of significant power? Quote Link to post Share on other sites
5e colin Posted December 29, 2015 Share Posted December 29, 2015 i would get a bung welded on its a sensor the ecu reads of as a safty feature to read conditions of engine funny tho i never seen a decat without a 02 sensor bung or are u on about the bottom lambda ( cat temp sensor ) Quote Link to post Share on other sites
adzy Posted December 29, 2015 Share Posted December 29, 2015 Is it an n/a?I forgot to plug mine in on the glanza when I fitted the decat and only noticed a week or more later, didn't notice any difference to drive tbh Quote Link to post Share on other sites
akyakapotter Posted December 29, 2015 Share Posted December 29, 2015 Is it an n/a?I forgot to plug mine in on the glanza when I fitted the decat and only noticed a week or more later, didn't notice any difference to drive tbhGlanza only uses it up untill about 2.5k then the map sensor takes over I believe Quote Link to post Share on other sites
Ollieh17 Posted December 29, 2015 Share Posted December 29, 2015 No difference on my wideeband with one plugged in or not Quote Link to post Share on other sites
morgey Posted December 29, 2015 Share Posted December 29, 2015 O2 sensor is used for idle and cruising, as soon as you put your foot down it switches away from o2 readings and to tps rpm and map readings and uses preset maps in the ecu for acceleration. Quote Link to post Share on other sites
Flynn Posted December 29, 2015 Share Posted December 29, 2015 Wonder if that's why mine idles like shit (4efte) when I swapped turbo kits we noticed mine wasn't connected. Car smells rich but I've wouldn't say it runs badly? Have been told running it without could cause it to run shitty and may lead to bore wash? Hopefully getting it sorted with a new O2 sensor tomorrow. Quote Link to post Share on other sites
4EFEJay Posted December 29, 2015 Author Share Posted December 29, 2015 Mines the 1.3 4efe NA. The new exhaust is fully decat straight through with one single resonator. I'm not sure if it was an O2, Lambda or Temp Sensor? Either way it does smell a bit rich. But not a big problem. I'll be driving it flat out 90% of the time! Unless i'm going to lose massive power or cause damage i'm not that worried. Quote Link to post Share on other sites
morgey Posted December 29, 2015 Share Posted December 29, 2015 O2/lambda its the same thing.the 4efte had a temp sensor for the cat as well as o2 sensor.Its going to smell a bit different without having the cat in there to filter out crap lol Quote Link to post Share on other sites
4EFEJay Posted December 30, 2015 Author Share Posted December 30, 2015 O2/lambda its the same thing.the 4efte had a temp sensor for the cat as well as o2 sensor.Its going to smell a bit different without having the cat in there to filter out crap lol Ok Thanks So if I run it without the O2 Sensor will that be ok for now? Should I look into getting it fitted back in? Quote Link to post Share on other sites
JayJ Posted December 30, 2015 Share Posted December 30, 2015 You will get better mileage and smoother running engine with lambda Quote Link to post Share on other sites
5e colin Posted December 30, 2015 Share Posted December 30, 2015 O2/lambda its the same thing.the 4efte had a temp sensor for the cat as well as o2 sensor.Its going to smell a bit different without having the cat in there to filter out crap lol not to my knowlidge morgey sensor 1 is always 02 sensor and sensor 2 is always bean lambda sensor thats how i was told in the classes donkeys ago Quote Link to post Share on other sites
StuDoc 72 Posted December 30, 2015 Share Posted December 30, 2015 o2 and lambda are the same. First ones o2 2nd one is cat temp sensor. Quote Link to post Share on other sites
Flynn Posted December 30, 2015 Share Posted December 30, 2015 Got mine fitted today, seems to drive exactly the same possibly idles a bit better but I'm pretty sure that could be my imagination. Time will tell with fuel consumption! Quote Link to post Share on other sites
JayJ Posted December 30, 2015 Share Posted December 30, 2015 Take out the EFI fuse to reset the ecu. Keep it off like 1 hour and put it back. Turn the car on and let it idle until warm. Otherwise it will take some time to notice the change. Quote Link to post Share on other sites
morgey Posted December 30, 2015 Share Posted December 30, 2015 not to my knowlidge morgey sensor 1 is always 02 sensor and sensor 2 is always bean lambda sensor thats how i was told in the classes donkeys ago More modern cars run 2 sensors. One pre cat and one post cat. One of these might be classed as a o2 to measure the % of o2/co2 (or monoxide) mix before the cat has done its job and then the one post cat will be measuring a known difference in o2 post cat and then correct the lambda to assist fueling.But on these cars one is a temp sensor and one is an o2/lambda. Quote Link to post Share on other sites
Flynn Posted December 30, 2015 Share Posted December 30, 2015 Been out in the car again and it does seem to run a bit better at lower revs and idle. It's a Jam ECU, would that be the same deal? Quote Link to post Share on other sites
5e colin Posted December 30, 2015 Share Posted December 30, 2015 thanks morgey Quote Link to post Share on other sites
Sefton-EP91 Posted December 30, 2015 Share Posted December 30, 2015 I ran my car with no 02 sensor for around 3 weeks and my MPG was awful, once i had fitted my new one (broke the old one) I noticed a massive difference in MPG. I was getting 50-55miles to £10 of v-power, with the new sensor connected id get 70-80miles without even trying! The same driving style in both occasions! Quote Link to post Share on other sites
Stu Posted December 31, 2015 Share Posted December 31, 2015 From my experience of running with and without and using my wideband to see the difference the lambda sensor is used for idle/cruise closed loop trims and when the engine is under load the ecu swaps to open loop control instead (no feedback from sensor). With the oxy plugged in the ecu does run richer in the idle/cruise area of the maps - possibly runs fail safe base settings (bit hard to tell without looking at the tune which isn't possible). With the oxy wired and working the trims do take a while adjust (possibly why the ecu has a constant 12v feed as a memory wire) but they do make quite a bit of difference depending on your atmospheric conditions and the fuel used etc. I'd recommend running one if you can. Quote Link to post Share on other sites
gorganl2000 Posted January 11, 2016 Share Posted January 11, 2016 a bit dated my post, but nonetheless, a few years back i was driving home and all of a sudden my ep91 felt sluggish and when i checked the "waste of money, cheap, Christmas tree, pretty light" afr guage i realised it was stuck in the "green/rich"....i pulled over, and checked the engine bay to see my 02 sensor wire broken.drove home with the car feeling sluggish and smelling somewhat of petrol. i reconnected the 02 sensor wire and immediately the car felt better....iirc i was running a JAM ecu at the time PS--those cheap afr guages are a waste, but it did seem to indicate the car was running very rich and helped me narrow my search...however, shortly after, i purchased a proper wideband afr system Quote Link to post Share on other sites
Flynn Posted January 11, 2016 Share Posted January 11, 2016 My car is running way better now the O2 sensors hooked up.......was defo running rich and the idle was low and lumpy! Quote Link to post Share on other sites
gorganl2000 Posted January 11, 2016 Share Posted January 11, 2016 i know back in the day some guys used to purposely disconnect the 02 sensor in order to run more fuel when they put on bigger turbos.....this method was even more crude than the fpr/fcd system i suspect the stock ecu goes in to some kind of "safe mode" when the 02 sensor is not detected and over fuels to protect the engine Quote Link to post Share on other sites
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