Imthatbyrd

So I'm new to Club Lexus and the SC world. I recently purchased a 1994 Lexus SC300 at the beginning of this week and I love it. Recently, I've noticed it would throw CEL after some time of driving and the light would turn off and on. I also noticed that I could smell a slight hint of exhaust fumes in the car when I would step hard on the gas. Along with those two other thing, I hear a noise (which I believe to be coming somewhere in the area of the center console on the exhaust) and I hear it when I accelerate more. When I get off the accelerator, I don't hear the noise, but when I step on the gas again, I hear it. By it being a 94, it's obd1 and I don't know anyone with an obd1 scanner. Lexus is asking $1xx just to run a diagnostic on the car which I find kinda pricey. Anyone have an ideas on what the problem could be before resulting in all of that before I end up having to pay for that diagnostic and then buy whatever possible part I need to buy?

scsexy

iTrader: (1)

Sounds like you have an exhaust leak.

you can use a paperclip connect t1 and te1 in the connector for a scan tool that's under the hood. your check engine light will flash and you can get the codes its stored like that. Just look up how to "read obd1 94sc400 codes" it's simple

Idlefree

Try stuffing a wet towel in the tailpipes and start the car and listen for the hiss if you can get underneath. Just an old trick, sometimes it works.

Good luck

mikef

iTrader: (3)

so you blow up the engine if there's no leak?

Idlefree

Obvious not for a long period of time, if thier is a leak usually you can hear pretty quickly, I've done this a few time and never blew an engine

RXRodger

iTrader: (2)

If the light stays on, make a jumper wire and cross TE1 and E1 in the diagnostic port, turn the key on and count the light flashes on the CEL. Use the table below. Come back here and tell us what you find.

As far as the exhaust leak, it is probably cracked at the pre-cat, very common place to break. You may also have broken motor mounts which cause this a lot of times, also very common. Does the exhaust smell like after catalytic converter smell? If you don't know what I mean, never mind. Also, a very good exhaust shop should have a smoke tester for finding an exhaust leak. Call around and find someone that has a smoke tester, basically it has a round plug that plugs into one exhaust outlet, plugs the other one and pushes smoke into the exhaust and comes out anywhere there is a leak.

Engine OBDI Diagnostic Codes
12 - RPM signal no. 1
13 - RPM signal no. 2
14 - Ignition no. 1 signal
15 - Ignition no. 2 signal
16 - ECT control signal
17 - No. 1 cam position sensor signal
18 - No. 2 cam position sensor signal
21 - Main oxygen sensor signal (on left bank)
22 - Water temp sensor signal
24 - Intake air temp. sensor signal
25 - Air-fuel ratio lean malfunction
26 - Air-fuel ratio rich malfunction
27 - Sub-oxygen sensor signal (on left bank)
28 - Main oxygen sensor signal (on right bank)
29 - Sub-oxygen sensor signal (on right bank)
31 - Air flow meter signal
35 - HAC sensor signal
41 - Throttle position sensor signal
43 - Starter signal
47 - Sub-throttle position sensor signal
51 - Switch condition signal
52 - No. 1 knock sensor signal
53 - Knock control signal
55 - No. 2 knock sensor signal
71 - EGR system malfunction
78 - Fuel pump control circuit fault

Cross TE1 and E1