1990 240sx : cel on

[sxconversion]

Ok, just bought this care about a month ago, the check engine light was on when i bought it, guy said he took it to mechanic and the said everything was ok and light was on because of loose wire. So i started looking into it. ECU flashed Red 3 green 2, meaning code 32 which is EGR, so i turned the car off, when to autozone to see how much a EGR valve was, 99 dollars, when i started the car back up, no CEL, about a block before i get home CEL comes on, check the code, 55, meaning everything ok. Why is my cel on if everything is ok??

[Touchdown038]

If it's running fine, and you don't have to worry about emissions, I wouldn't worry about replacing the valve, or even for the engine light for that matter. It really is a pain to get to, as close to the firewall as it is. You can probably just get away with cleaning the rubber hoses with b12 just to make sure there are no carbon chunks in there.

[NISTECH]

I would venture to say 99% of check engine light codes for EGR are NOT the valve. Its typically something with the BPT or the solonoid. On a 90 240 my guess would be the egr solonoid has excessive resistance.

[sxconversion]

how, and acually where are the egr solonoid, sorry for such a long time, i have been without a computer for some time. But anyway, where is the solonoid, because i cleaned the egr out and it is like new, lot stuff in there. The thing is i need to pass emission this is the only reason i am acually fixing it, because in a month i am gettin the SR

[NISTECH]

The solonoid is on the side of the intake down near the bottom and more forward of center of the intake. The connector is a bit of a pita to get off but once you do use an ohm meter to test the solonoid across the 2 terminals.

[sxconversion]

id

The solonoid is on the side of the intake down near the bottom and more forward of center of the intake. The connector is a bit of a pita to get off but once you do use an ohm meter to test the solonoid across the 2 terminals.

any idea how much resistance should be there??

[NISTECH]

about 40 ohms

[sxconversion]

about 40 ohms

could my egr valve be leaking, because when i cleaned it out, it didnt hold carb clean in the body of the valve it leaked into the exhaust side of the egr, this could explain why at lower rpms my car has a stumble in it??

[NISTECH]

Depending on how much open it is yes. They dont always sit completely tight and a Very small gap will be neglagable to engine idle.

[sxconversion]

Depending on how much open it is yes. They dont always sit completely tight and a Very small gap will be neglagable to engine idle.

Ok, i havent checked the solonoid yet, but i was wondering just for a idea on this, how does the egr valve acually turn on the cel light, acually i should say what stops it from turning it on, if i could bypass that it would be great, because i would just get egr blockoff plates and say the hell with it?? any ideas i wish i had a manual to use the wiring diagram that way i wouldnt have to ask as much

[NISTECH]

It throws the code if it doesnt "see" the solonoid in the circuit, if it doesnt see a voltage drop when it activates the circuit, if you have an egr temp sensor it also will throw a code if it doesnt see a voltage drop on that circuit when the egr is suppose to be flowing.

[sxconversion]

It throws the code if it doesnt "see" the solonoid in the circuit, if it doesnt see a voltage drop when it activates the circuit, if you have an egr temp sensor it also will throw a code if it doesnt see a voltage drop on that circuit when the egr is suppose to be flowing.

can i just put a resistor like they said 100k ohm in between the two wires going to the temp sensor?? no one has acually said if this works or not

[NISTECH]

The EGR temp sensor looks for a voltage change when the egr is suppose to be in operation. It goes either way. If it sees to low of voltage at idle or when it doesnt expect to see flow it determines there is an EGR fault. When it doesnt see a low enough voltage when it expects it to it will determine its got an egr system failure. So I dont see how a resistor would be able to offer both circumstances.

If you are trying to get through a smog check and you eliminate the system, you will fail the tail pipe test for NOx.