1998 Ford Mustang P1150 P1151 P1152 and P0174 Error Codes: O2 Sensor or Fuel Mixture Issue?

The fuel air mixture is off — that's the core issue. Have you tried any repairs yet, such as cleaning or replacing components?

I'm planning to replace all four O2 sensors tomorrow and take it to Auto Zone for a free diagnostic test. I just learned they offer this — though I’m not fully confident it will resolve the issue since the codes are broad. Still, I’ll try it first. Thanks for the tip!

Auto Zone doesn’t perform diagnostics — they only read stored codes. The cost of O2 sensors is better spent on a proper diagnostic scan. Have you checked for vacuum leaks or cleaned your MAF sensor? Those are more likely root causes than just replacing sensors.

Jeff — you're right, Auto Zone doesn’t do diagnostics! I took it to Ford and they said no leaks were found but gave me a $1200+ quote for repairs. They claimed the work might not solve the problem. After asking about their plan, they said replacing all four O2 sensors would cost $600 in parts ($150 each) plus 6 hours of labor at $110/hour — which totals over $1200. I bought the parts for $200 total and will replace them this week. The O2s had visible carbon buildup, so they suggested replacement. After that, I plan to perform the work they recommended. However, I haven’t checked for vacuum leaks yet — what’s the best way to test for those? Thanks!

Hi there — did changing the O2 sensors fix your issue? I have a similar code set on my 1999 Mustang. The car runs rough when cold and during acceleration from idle. I’ve already done a tune-up and cleaned the MAF sensor, and no leaks are visible. Have you tried replacing the sensors? Was it easy to do? Any tips for success?

Thierryp — all my codes cleared after I replaced: 1) All four O2 sensors (I only needed two, but changed all four) 2) The camshaft position sensor Parts cost: ~$50 per O2 sensor ($200 total), $35 for the camshaft sensor. O2 sensor replacement is straightforward — just loosen and pull out the old ones, install new ones, and tighten. Replacing all four takes about 30 minutes. I recommend using a lift to make it easier. The camshaft sensor took around an hour — not difficult to change, but access can be tricky. I also cleaned my MAF since it’s simple and effective — easy to remove, clean, and reinstall. I strongly suggest doing this yourself — auto shops charge high rates. I spent $230 total for two hours of work, while they quoted 6 hours at $1250. If you have the same codes, start with O2 sensors. Hope this helps!

FYI, not all O2 sensors are easy to replace — especially on rear bank of a 3.3L Taurus or front bank downstream in a '96 Chrysler 3.3L. Replacing them without damaging vacuum lines or wiring can be extremely challenging. If you're doing it yourself, be prepared for significant difficulty and risk. I don’t offer free work — if you bring your vehicle to my shop for all four O2s, expect $200–$250 in labor. DIY is your best option if you’re serious about avoiding high repair costs.

I'm an ASE-certified and Ford factory-trained technician. I've worked on vehicles for over 25 years — I’ve never seen all four O2 sensors fail simultaneously. A code doesn’t mean you need to replace parts. You have a fuel mixture control issue. If the MAF is clean and functioning properly, then the problem lies in fuel delivery — possibly due to incorrect O2 sensor inputs, vacuum leaks, low/high fuel pressure (from a leaking regulator or vacuum port), injector failure, or mechanic error. Without additional symptoms or codes, it's highly unlikely that any single O2 sensor is at fault. The real issue is likely elsewhere. Focus on diagnostics before part replacement — good luck!