No CEL in first start up but always appears on second

[blastnpast]

Installed b18c7 standard ecu into my EK with a b16a2 drives well however when first start up I get no CEL codes and the car takes longer to return to idle once placed in neutral after accelerating but when I turn off and start back up a CEL code is up (02 sensor) and the car drives normal with the revs returning to 1,300 when placed in neutral my questions are :

-How come the CEL code doesn't pop up right away on first start up?

-after driving without the CEL why do the revs take Longer To get back down to idle?

-when driving with the CEL how come the car drives normal and revs are brought down as soon as acceleration is released?

[ECU-MAN]

its the opposite

its normal for the revs to drop slowly and not normal for the revs to quickly drop.


when your cel is on your ECU could have trigered limp mode, so infact the ECU runs from a different processor and ROM


if you have a faulty O2 the ECU will detect that edventually on the first start up.

[blastnpast]

its the opposite

its normal for the revs to drop slowly and not normal for the revs to quickly drop.


when your cel is on your ECU could have trigered limp mode, so infact the ECU runs from a different processor and ROM


if you have a faulty O2 the ECU will detect that edventually on the first start up.

Lol thanks ecu-man so what am I experiencing here? Is my ecu fault or is it some weird crap going on?

[Benson]

Change the o2 sensor and see how you go

[blastnpast]

Change the o2 sensor and see how you go


I'll change it and I think I don't actually have the second sensor - I have the headers one however dont think the one near the cat is evident I'll have to look

[ECU-MAN]

is the O2 in the hole after all the pipes from the port meet, or in the hole on a single pipe.

I cant tell you if you have an ECU, wiring, or sensor fault without looking at the car. These things need to be diagnosed

[blastnpast]

CEL codes were read and they are

17 & 23

Knock sensor (currently not plugged in and dont know where it plugs in lol?)

VSS will have to investigate this problem!

Do any of these CEL codes alter the car's performance?

[blastnpast]

Any takers on helping me out

[dorikin]

Did you actually wire in the Knock Sensor when you did the conversion?

[hasto2770]

Did you actually wire in the Knock Sensor when you did the conversion?

Valid point but I think he did seeming he said he has the plug there from the harness

[blastnpast]

Ok guys, the knock sensor was plugged back in last night, I drove it this morning the same thing still happeneds and when the clutch is engaged it idles up to 3,000 rpms, then slowly drops down however on it's way dropping down it springs back up and fluctuates until it has had enough and eventually drops down to idle point.

I turned engine off and on again it didn't give me any CEL codes this time however when the clutch is engaged the idle goes up to 1,500 rpms and slowly begins to drop to 1,100 however it springs up to 1,500 and fluctuates before having enough and idles down to 1,100 lol **** me this Is really needing some mechanical assistance

[ECU-MAN]

you have IACV problems

ensure you do not have any vacuum leaks and that your cars isnt running to rich or lean at idle or near idle RPM's

[blastnpast]

you have IACV problems

ensure you do not have any vacuum leaks and that your cars isnt running to rich or lean at idle or near idle RPM's

I have checked for vaccume leaks b4 but I will check again, my car prob is running rich due to the b18 ecu on my b16 engine however I will be getting an ek4 ecu and connecting it up

Thanks in advance everyone

[ECU-MAN]

if your running B18C ECU on the B16 then expect it to idle funny

[blastnpast]

if your running B18C ECU on the B16 then expect it to idle funny

Thanks for this I am gonna install b16 ecu tonight fingers crossed

[ECU-MAN]

good luck

let us know how you get on with it.