rebuiltSI

This is on a 99 Si: So I tried to replace my Secondary o2 sensor because of a Cat efficiency code (P0420). I used a universal Denso 4-wire sensor. I believe I wired everything correctly, so I plugged it back in and immediately the CEL came back on. I got the CEL read and it said P0141 (malfunction exists in the heater circuit for oxygen sensor 2 in bank 1). So I took it apart and reconnected the wires, crimped them, and used shrink wrap. I plugged it back in and immediately the CEL came back on. I got the CEL read and it came up with 4 codes!!! This is the list of codes:

P0500 (malfunction exists in the electrical circuit for the vehicle speed sensor)
Note- my odometer is not working now

P1298 (Electrical Load Detector Circuit Input High)
Replaced a burnt out fuse, #15 on the fuse box under the dash

P0135 (malfunction exists in the heater circuit for oxygen sensor 1 in bank 1)


Can anyone help me? Also, after I replaced the fuse #15 it blew out when I turned the car on again.

tech8

Your O2 wires are probably shorting against something, and causing the other trouble codes, in addition to the blown #15 fuse.

rebuiltSI

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tech8 &raquo;</TD></TR><TR><TD CLASS="quote">Your O2 wires are probably shorting against something, and causing the other trouble codes, in addition to the blown #15 fuse. </TD></TR></TABLE>

You made me think of something. When I spliced the wires together I used the metal connectors the you use in between the seperate wires to crimp them together. Well I think those metal pieces are touching cause they are shrink wrapped together. Hope thats it. Im going to go take it apart right now.

truevietluv636

maybe you have to reset the ecu. not sure though.

tech8

Almost guaranteed that a short in the O2 wires are causing the other codes and blown #15 fuse.

Syndacate

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tech8 &raquo;</TD></TR><TR><TD CLASS="quote">Almost guaranteed that a short in the O2 wires are causing the other codes and blown #15 fuse.</TD></TR></TABLE>

Yeah, either that or he wired it wrong.

If you're 100% sure it's wired right, go under your dashboard, check the fuse in the 2nd row down, 5th row from the left (fuse #15), if it's blown it's shorting out someplace - you're speedometer also won't work and you might throw a code 20 for an electronic surge.

It sounds as though the wires as touching on the secondary O2, like you messed up the wiring or something. If it was grounding out to the chassis like tech8 said it'd pop that fuse and you'd throw a code 20 (electronic load) and your vehicle speed sensor wouldn't work (you wouldn't have a speedometer) and you'd be throwing an both O2 sensor heater lights.

Oh yeah, and your alternator won't charge your battery...it's pretty noticeable stuff.

I'm like 99.9999% sure you messed up the wiring when you hooked up the universal O2 - universal O2's SUCK for this reason right here.

Either they're touching, or they're not wrapped right, or you mixed up the O2 sensor heater wires, or something to that effect...check the wiring...then check the wiring...then check the wiring...then after you did that, reset the ECU, and check the wiring again - it's messed up, I'm almost willing to bet money that's where the issue is.

If it was a short like tech8 said it'd pop that fuse...again...that'd be from an exposed wire when you hooked it up...

tech8

The short could be either his O2 wire grounding out against the chassis, or that the O2 wires are touching each other (e.g., (+) signal touching (-) signal, etc.).

rebuiltSI

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tech8 &raquo;</TD></TR><TR><TD CLASS="quote">The short could be either his O2 wire grounding out against the chassis, or that the O2 wires are touching each other (e.g., (+) signal touching (-) signal, etc.).</TD></TR></TABLE>

Bingo.. the O2 wires were crimped together using the metal connectors in the Universal o2 Sensor kit. The connectors where touching each other and causing it to short/blow the #15 fuse. I fixed the problem by wrapping each connector in electrical tape. Im a legitimate noob mechanic, but I never give up. Thanks guys for the help/recommendations.

tech8

Glad you got it fixed. for DIY.

rebuiltSI

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tech8 &raquo;</TD></TR><TR><TD CLASS="quote">Glad you got it fixed. for DIY.</TD></TR></TABLE>

I patted myself on the back.. a small DIY fix still feels good.