Maruti Zen MIL is on

mclaren1885 · 1st October 2007, 00:10

Mohnish, my understanding of "limp mode" is when the ECU limits the characteristics of the engine and drops power drastically or doesn't allow you to rev past 3500 rpm (or whatever the rpm set by a manufac). None of this happened when my EGR or O2 sensor were disconnected. IIRC, the O2 sensor on your car too had conked off but I remember you telling me that there was no drop in performance except that your car gave really low FE.

I am quite sure that there was no drop in performance or that the ECU did not send the car into "limp mode" as per my understanding. If you still have doubts, you might want to get the same clarified with psycho. Or maybe wait till someone like Rdkarthik can clarify this. Because I was told by psycho that there was no harm in running with the O2 not connected.

I also know that you guys are far more technically sound than I am. I am just reporting what I saw with my own eyes over a period of 3 months (the time during which I ran with the MIL light on). So pardon my ignorance & do correct me if I am wrong. I am here to learn, maybe if you are right that could have been one of the primary reasons for the cause of concern on my car. And the reason for the rebuilds. But I would like to make sure before I take a stand on this.

rr_zen · 21st October 2007, 07:22

I had the engine oil replaced for my Honda Civic yesterday and have driven about 10 miles since the oil was replaced. Today, I started the car and the check engine light came on a few seconds later. I am planning to take it back to the service station tomorrow. What could be the problem ? I have read in the above posts that the light comes on if the engine oil has not been changed for a long time but my scenario here seems to be exactly the opposite.

1st October 2007, 00:10	#16
mclaren1885 BANNED Join Date: Jul 2005 Location: Bangalore (the city of modded cars) !! Posts: 4,820 Thanked: 45 Times View My Garage Infractions: 0/1 (10)	Mohnish, my understanding of "limp mode" is when the ECU limits the characteristics of the engine and drops power drastically or doesn't allow you to rev past 3500 rpm (or whatever the rpm set by a manufac). None of this happened when my EGR or O2 sensor were disconnected. IIRC, the O2 sensor on your car too had conked off but I remember you telling me that there was no drop in performance except that your car gave really low FE. I am quite sure that there was no drop in performance or that the ECU did not send the car into "limp mode" as per my understanding. If you still have doubts, you might want to get the same clarified with psycho. Or maybe wait till someone like Rdkarthik can clarify this. Because I was told by psycho that there was no harm in running with the O2 not connected. I also know that you guys are far more technically sound than I am. I am just reporting what I saw with my own eyes over a period of 3 months (the time during which I ran with the MIL light on). So pardon my ignorance & do correct me if I am wrong. I am here to learn, maybe if you are right that could have been one of the primary reasons for the cause of concern on my car. And the reason for the rebuilds. But I would like to make sure before I take a stand on this.
	() Thanks

21st October 2007, 07:22	#17
rr_zen Senior - BHPian Join Date: Sep 2006 Location: Chennai, India Posts: 1,799 Thanked: 400 Times View My Garage	I had the engine oil replaced for my Honda Civic yesterday and have driven about 10 miles since the oil was replaced. Today, I started the car and the check engine light came on a few seconds later. I am planning to take it back to the service station tomorrow. What could be the problem ? I have read in the above posts that the light comes on if the engine oil has not been changed for a long time but my scenario here seems to be exactly the opposite.
	() Thanks