Code 45 on a 91 240SX -- NON California car!!!

[sethulrich]

Help!! I just checked the codes on my 91 240SX, and got code 45 (leaky injectors). But I thought code 45 was only for CA cars! I am the third owner of the car, and the original bill of sale from Indiana is still with the owners manual in the glove box.... soo......what gives? is code 45 still a valid code for non CA cars? The only other thing I could think of is that it's actually two codes: 11 (cam position sensor) and 25 (IACV-AAC Valve). Is that possible? And the code isn't going away either....I checked it a couple weeks ago, reset it, and just checked it again now, and there it is again. It is not throwing a CEL, i just checked it for the heck of it....because I just bought the car.

A little more info: the car gets worse mileage (about 25 mpg) than my 93 240sx (30+ mpg) over the same driving conditions, and it also seems that the 93 has a bit more power. The 93 has 265k on the clock, the 91 only has about 150k, for what it's worth. Both cars are relatively stock. (Intake, and electric fan conversion on both of them)

Any help with these code would be greatly appreciated.

Thanks!!!!

[NISTECH]

You need to sweep check the O2 It may be costantly reading rich, You should be able to pull a vaccum line and see its voltage drop below .175 volts if it doesnt then its likley shifted rich. Also you could take a look at your F/P regualtor make sure it changes fuel pressure properly, spec is 36psi@idle and 41 on accel. be sure it is not sucking fuel in through the vaccum line.

What your code means is the ecm sees a constantly rich signal even when it tries to lean it out and it cant do it.

[sethulrich]

Thanks for responding, NISTECH.

So let me get this straight:

Scenario 1: pull vaccum line, voltage doesn't drop indicating it's shifted rich.

Solution: Replace O2 sensor?

Scenario 2: FP reg is out of spec.

Solution: Replace regulator?

Scenario 3: sucking fuel thru vaccum line. (or is this merely a result of scenario 1 or 2)

Solution: ???

[NISTECH]

senario 1 if you pull off say the brake booster vaccum line and the car will still run and the voltage does not shoot down to 0v or close to it yes your O2 is shifted, if you pull the line and the car dies you need to kinda lean the line so it wont die but will create a serious vaccum leak, Do not pull the fuel pressure regulator vaccum line as that will richen the car up. If it wont drop replace the O2.

If the F/P reg giving a 41psi or higher and it has vaccum to it at idle, yes replace it.

If it is letting fuel pass into the vaccum line,yes replace it.

[NateDogg]

Code 45 is leaky injectors. Pull your spark plugs with the key to 'ON'. This will pressurize the fuel system. If there's a leak, this may induce a leak in the injector and show on the coinciding plug as wet fuel. You may also be able to tell by the darker colored plugs which may be the ones leaking.

At idle, the fuel pressure should be 43 psi without the vacuum line connected to the regulator and 34 psi with it connected.