1997, 1.5 engine coolant temperature sensor question
#1
12-31-2013, 12:40 PM
1997, 1.5 engine coolant temperature sensor question
1997 1.5, engine coolant temperature sensor (getting a catalytic converter CEL)
I'm probably going to end up buying a new upstream cat for my 1997 protege 1.5 manual.
the car has 120K on it, and I've only owned it about 5k
I've done LOTS of service on it, eliminated 3 or 4 check engine lights, new IAC, cleaned EGR, timing belt, water pump, plugs and wires, cap-rotor, replaced the distributor due to a coil problem, both O2 sensors new, etc......
my guess is that my intermittent ignition mis-fire probably damaged the catalytic converter
but before I buy a new expensive cat, I wanted to rule out everything that could possibly cause the 420CEL
so I've tripple checked my timing
I've had witch-hunter rebuild my injectors
and I'm reading other possible causes of a P0420 are:
1) exhaust leak in manifold (wouldn't I hear this... I don't seen or hear anything but is there a better way to check?)
2) down stream o2 not working (I have replaced this with new)
3) engine coolant temperature sensor not working properly
so here is my real question
is there a seperate coolant temperature sensor for the computer and for the dash water temp gauge?
I have replaced the thermostat and my dash gauge is functioning normal
does the computer use a different coolant temp input that could be my culprit?
thanks in advance anyone
brant
the car has 120K on it, and I've only owned it about 5k
I've done LOTS of service on it, eliminated 3 or 4 check engine lights, new IAC, cleaned EGR, timing belt, water pump, plugs and wires, cap-rotor, replaced the distributor due to a coil problem, both O2 sensors new, etc......
my guess is that my intermittent ignition mis-fire probably damaged the catalytic converter
but before I buy a new expensive cat, I wanted to rule out everything that could possibly cause the 420CEL
so I've tripple checked my timing
I've had witch-hunter rebuild my injectors
and I'm reading other possible causes of a P0420 are:
1) exhaust leak in manifold (wouldn't I hear this... I don't seen or hear anything but is there a better way to check?)
2) down stream o2 not working (I have replaced this with new)
3) engine coolant temperature sensor not working properly
so here is my real question
is there a seperate coolant temperature sensor for the computer and for the dash water temp gauge?
I have replaced the thermostat and my dash gauge is functioning normal
does the computer use a different coolant temp input that could be my culprit?
thanks in advance anyone
brant
#2
12-31-2013, 02:21 PM
PO420 means Cat warm up efficiency below threshold. The threshold is 95%. So your cat may be only 94% efficient and you get that blasted code. Maybe there is some stuff affecting the flow. You could try this cleaning method:
Use 1gal of lacquer thinner (NOT PAINT THINNER!) and pour it in a half full tank. Then drive that thing for about 100 miles, but keep the rotations below 5000 per minute.
I have done that in my vehicles and all of them ran better after that cleaning. Often times it clears enough debris from the cat to bring back above the efficiency threshold.
If this engine was ever treated with bars leaks or similar the ECT sensor may have been coated with this stuff affecting the reading. ECT sensors are very reliable.
I do not know if the instrument gauge has it's own sending unit.
Use 1gal of lacquer thinner (NOT PAINT THINNER!) and pour it in a half full tank. Then drive that thing for about 100 miles, but keep the rotations below 5000 per minute.
I have done that in my vehicles and all of them ran better after that cleaning. Often times it clears enough debris from the cat to bring back above the efficiency threshold.
If this engine was ever treated with bars leaks or similar the ECT sensor may have been coated with this stuff affecting the reading. ECT sensors are very reliable.
I do not know if the instrument gauge has it's own sending unit.
Last edited by tanprotege; 12-31-2013 at 02:24 PM.
#3
12-31-2013, 02:36 PM
^^^^^^
what Tan said! Definitely the easiest thing to do first and cheapest!
Remember lacquer thinner, not paint thinner. It is clearly marked on the can.
what Tan said! Definitely the easiest thing to do first and cheapest!
Remember lacquer thinner, not paint thinner. It is clearly marked on the can.
#5
12-31-2013, 06:37 PM
tanprotege,
cool thanks for the link
I'll re-check the O2 sensors for grounding/tightness
although I put both of them in new about 5K ago myself and the threads were clean and tight....
I'm afraid to pour laquer thinner into it honestly
I don't want to effect anything in the fuel system... (pump, injectors, etc)
as soon as I rule out the last 2 possibles on the list (exhaust leak, failing coolant temperature sender) I'll probably just buy a new cat.
bump...
anyone know if the car has more than one coolant temperature sender (1 for the gauge, and one for the ECM?)
cool thanks for the link
I'll re-check the O2 sensors for grounding/tightness
although I put both of them in new about 5K ago myself and the threads were clean and tight....
I'm afraid to pour laquer thinner into it honestly
I don't want to effect anything in the fuel system... (pump, injectors, etc)
as soon as I rule out the last 2 possibles on the list (exhaust leak, failing coolant temperature sender) I'll probably just buy a new cat.
bump...
anyone know if the car has more than one coolant temperature sender (1 for the gauge, and one for the ECM?)
#7
01-01-2014, 09:57 PM
Ok... there is only one coolant temp sensor on a 1997
I unplugged it and ran the test cold
(its a little on the low side cold)
but then ran the car for 15 minutes in the garage
the water temp gauge on the dash was pegged at cold.
the sensor numbers came down to within the range they should of for warm
I plugged the sensor back into its loom and suddenly the gauge on the dash is in the low operating region Just for kicks I pulled the exhaust manifold shield and looked everything over again. no visible cracks and more importantly, no sign of heat marks or carbon marks.. I am 99% sure there are no exhaust cracks at this point.
I don't have a scope to verify the O2's again... but I did have a shop run that for me last month.
looks like I'm saving for a walker primary cat now.
I unplugged it and ran the test cold
(its a little on the low side cold)
but then ran the car for 15 minutes in the garage
the water temp gauge on the dash was pegged at cold.
the sensor numbers came down to within the range they should of for warm
I plugged the sensor back into its loom and suddenly the gauge on the dash is in the low operating region Just for kicks I pulled the exhaust manifold shield and looked everything over again. no visible cracks and more importantly, no sign of heat marks or carbon marks.. I am 99% sure there are no exhaust cracks at this point.
I don't have a scope to verify the O2's again... but I did have a shop run that for me last month.
looks like I'm saving for a walker primary cat now.
#8
01-01-2014, 10:24 PM
tanprotege,
cool thanks for the link
I'll re-check the O2 sensors for grounding/tightness
although I put both of them in new about 5K ago myself and the threads were clean and tight....
I'm afraid to pour laquer thinner into it honestly
I don't want to effect anything in the fuel system... (pump, injectors, etc)
as soon as I rule out the last 2 possibles on the list (exhaust leak, failing coolant temperature sender) I'll probably just buy a new cat.
bump...
anyone know if the car has more than one coolant temperature sender (1 for the gauge, and one for the ECM?)
cool thanks for the link
I'll re-check the O2 sensors for grounding/tightness
although I put both of them in new about 5K ago myself and the threads were clean and tight....
I'm afraid to pour laquer thinner into it honestly
I don't want to effect anything in the fuel system... (pump, injectors, etc)
as soon as I rule out the last 2 possibles on the list (exhaust leak, failing coolant temperature sender) I'll probably just buy a new cat.
bump...
anyone know if the car has more than one coolant temperature sender (1 for the gauge, and one for the ECM?)
Make sure you drive for at least an hour right after putting it in, keeping revs below 5000.
Magnaflow sells the front cat: MagnaFlow 49 State Converter Direct Fit Catalytic Converter - 50671 - Marken Performance & Restoration Inc. + labor.
Rear one: http://markenperformance.com/lookup.html?search=50672
http://magnaflow.com/02catalytic_con...irectfit=50671
http://magnaflow.com/02catalytic_con...irectfit=50672
http://magnaflow.com/02converters.asp from here pick if you are California, New York or Rest (federal) and then input your vehicle.
Last edited by UseYourNoggin; 01-01-2014 at 10:36 PM.
#9
01-02-2014, 09:57 AM
Brant: UseYourNoggin has a way with words! (Get used to it) But he is right. I would not recommend using Scotty's method if I hadn't tried myself. An I did it in 3 different cars, one of them was the 98 Protege 1.5L.
I have the feeling you like to throw parts at a problem. I am sure at some point you will have the problem solved, but at a significant expense. I prefer $5 solutions over $500 solutions.
Also: if you replace the cat, you need to take the old one out first. That would be a perfect opportunity to inspect it and if dirty wash it with laundry detergent.
All the best for 2014!
I have the feeling you like to throw parts at a problem. I am sure at some point you will have the problem solved, but at a significant expense. I prefer $5 solutions over $500 solutions.
Also: if you replace the cat, you need to take the old one out first. That would be a perfect opportunity to inspect it and if dirty wash it with laundry detergent.
All the best for 2014!
Last edited by tanprotege; 01-02-2014 at 10:01 AM.
#10
01-02-2014, 10:43 AM
I threw parts at the car mostly because I bought it just under 120K and the previous owner had done zero maintenance. It had about 4 check engine lights on, the thermostat was out, the intake boot torn, the EGR stuck, the boost sensor dead, and the water pump leaking... oh yeah... original timing belt
So I did buy a lot of necessary parts
I did just have witch hunter rebuild the fuel injectors, and mostly because I knew the prior owner was terrible at maintenance and new they had never been cleaned.
so I would hate to damage these brand new injectors with solvent.
but let me ask a few questions about the laquer thinner
the video recommends 1 gallon
-how much did each of you add, and ontop of how much gasoline in the tank?
-were you having catalytic converter problems before (P0420) that were curred by the treatment?
-how many miles have you driven since the treatment and did any seals, fuel pumps or other problems occur after thousands or tens of thousands of miles?
thanks for all the help and thanks for answering the 3 questions
I'm considering it, but also trying to be cautious and educate myself.
brant
So I did buy a lot of necessary parts
I did just have witch hunter rebuild the fuel injectors, and mostly because I knew the prior owner was terrible at maintenance and new they had never been cleaned.
so I would hate to damage these brand new injectors with solvent.
but let me ask a few questions about the laquer thinner
the video recommends 1 gallon
-how much did each of you add, and ontop of how much gasoline in the tank?
-were you having catalytic converter problems before (P0420) that were curred by the treatment?
-how many miles have you driven since the treatment and did any seals, fuel pumps or other problems occur after thousands or tens of thousands of miles?
thanks for all the help and thanks for answering the 3 questions
I'm considering it, but also trying to be cautious and educate myself.
brant